Waterfowl population status, 2006

              Waterfowl
Population Status, 2006
U.S. Fish and Wildlife Service
WATERFOWL POPULATION STATUS, 2006
July 25, 2006
In North America the process of establishing hunting regulations for waterfowl is conducted annually. In the
United States the process involves a number of scheduled meetings in which information regarding the status of
waterfowl is presented to individuals within the agencies responsible for setting hunting regulations. In addition
the proposed regulations are published in the Federal Register to allow public comment. This report includes
the most current breeding population and production information available for waterfowl in North America and is
a result of cooperative efforts by the U.S. Fish and Wildlife Service (FWS), the Canadian Wildlife Service
(CWS), various state and provincial conservation agencies, and private conservation organizations. This report
is intended to aid the development of waterfowl harvest regulations in the United States for the 2006-2007
hunting season.
________________________________________________________________________________________
Cover: 2006-2007 Duck stamp. Ross’ goose by Sherrie Russell Meline, winner of the 2006-2007 Federal Duck Stamp
design competition.
ACKNOWLEDGMENTS
Waterfowl Population and Habitat Information: The information contained in this report is the result of the efforts
of numerous individuals and organizations. Principal contributors include the Canadian Wildlife Service, U.S.
Fish and Wildlife Service, state wildlife conservation agencies, provincial conservation agencies from Canada,
and Direccion General de Conservacion Ecologica de los Recursos Naturales, Mexico. In addition, several
conservation organizations, other state and federal agencies, universities, and private individuals provided
information or cooperated in survey activities. Some habitat and weather information was taken from the
NOAA/USDA Joint Agriculture Weather Facility (http://www.cpc.ncep.noaa.gov/index.html), Environment
Canada (http://www.pnr-rpn.ec.gc.ca/index.en.html), and Waterfowl Population Surveys reports
(http://migratorybirds.fws.gov/reports/reports.html). Appendix A provides a list of individuals responsible for the
collection and compilation of data for the Ducks section of this report. Appendix B provides a list of individuals
who were primary contacts for information included in the Geese and Swans section. We apologize for any
omission of individuals from these lists, and thank all participants for their contributions. Without this combined
effort, a comprehensive assessment of waterfowl populations and habitat would not be possible.
Authors: This report was prepared by the U.S. Fish and Wildlife Service, Division of Migratory Bird
Management, Branch of Surveys and Assessment. The principal authors are Pamela R. Garrettson, Timothy J.
Moser, and Khristi Wilkins. The authors compiled information from the numerous sources to provide an
assessment of the status of waterfowl populations.
Report Preparation: The preparation of this report involved substantial efforts on the part of many individuals.
Support for the processing of data and publication was provided by Mark C. Otto and John Sauer. Ray Bentley,
John Bidwell, Karen Bollinger, Elizabeth Huggins, Bruce Conant, Carl Ferguson, Rod King, Mark Koneff, Fred
Roetker, John Solberg, Phil Thorpe, Dan Nieman, Dale Caswell, James Dubovsky, Robert Blohm, and James
Wortham provided habitat narratives, reviewed portions of the report that addressed major breeding areas, and
provided helpful comments.
This report should be cited as: U.S. Fish and Wildlife Service. 2006. Waterfowl population status, 2006. U.S.
Department of the Interior, Washington, D.C. U.S.A.
All Division of Migratory Bird Management reports are available at our home page
(http://www.fws.gov/migratorybirds).
Table of Contents
ACKNOWLEDGMENTS.................................................................................................................... 2
Status of Ducks
METHODS ........................................................................................................................................ 5
RESULTS AND DISCUSSION........................................................................................................... 7
REFERENCES.................................................................................................................................. 30
Status of Geese and Swans
METHODS ........................................................................................................................................ 31
RESULTS AND DISCUSSION........................................................................................................... 33
Appendices
Appendix A. Individuals who supplied information on the status of ducks ....................................... 47
Appendix B. Individuals who supplied information on the status of geese and swans..................... 49
Appendix C. Strata and transects of the Waterfowl Breeding Population and Habitat Survey......... 51
Appendix D. Estimated number of May ponds and standard errors in portions of Prairie and
Parkland Canada and the northcentral U.S. ......................................................................... 52
Appendix E. Breeding population estimates for total ducks and mallards for states, provinces,
or regions that conduct spring surveys ................................................................................. 53
Appendix F. Breeding population estimates and standard errors for 10 species of ducks
from the traditional survey area ............................................................................................ 55
Appendix G. Total breeding duck estimates for the traditional survey area, in
thousands............................................................................................................................. 57
Appendix H. Breeding population estimates and 95% confidence intervals or credibility intervals
for the 10 most abundant species of ducks in the eastern survey area……………………...58
Appendix I. Population indices for North American Canada goose populations, 1969-2005 ........... 59
Appendix J. Population indices for light goose, greater white-fronted goose, brant, emperor
goose, and tundra swan populations during 1969-2005....................................................... 60
3
List of Duck Tables
Table 1. Estimated number of May ponds in portions of Prairie and Parkland Canada and the
northcentral U.S. ................................................................................................................ 9
Table 2. Total duck breeding population estimates .......................................................................... 12
Table 3. Mallard breeding population estimates ............................................................................... 13
Table 4. Gadwall breeding population estimates.............................................................................. 19
Table 5. American wigeon breeding population estimates ............................................................... 19
Table 6. Green-winged teal breeding population estimates ............................................................. 20
Table 7. Blue-winged teal breeding population estimates ................................................................ 20
Table 8. Northern shoveler breeding population estimates .............................................................. 21
Table 9. Northern pintail breeding population estimates .................................................................. 21
Table 10. Redhead breeding population estimates .......................................................................... 22
Table 11. Canvasback breeding population estimates ..................................................................... 22
Table 12. Scaup (greater and lesser combined) breeding population estimates ............................. 23
Table 13. Duck breeding population estimates for the 10 most abundant species in the
eastern survey area ........................................................................................................... 23
List of Duck Figures
Figure 1. Number of ponds in May and 90% confidence intervals for Prairie and Parkland
Canada and the northcentral U.S. ..................................................................................... 9
Figure 2. Breeding population estimates, 90% confidence intervals, and North American
Waterfowl Management Plan population goal for selected species for the traditional
survey area ........................................................................................................................ 14
Figure 3. Breeding population estimates and 95% credibility intervals for selected species in
the eastern survey area ...................................................................................................... 17
Figure 4. Breeding population estimates and 95% confidence intervals for selected species in
the eastern survey area ...................................................................................................... 18
Figure 5. Estimates and 90% confidence intervals for the size of the mallard population in the
fall....................................................................................................................................... 30
List of Goose and Swan Figures
Figure 1. Important goose nesting areas in arctic and subarctic North America ............................. 32
Figure 2. Snow and ice cover in North America for spring ............................................................... 33
Figure 3. Approximate ranges of Canada goose populations in North America............................... 34
Figures 4-18. Indices to Canada goose populations’ status ............................................................ 33-40
Figure 19. Approximate ranges of selected goose populations in North America............................ 41
Figures 20-27. Indices to selected goose populations’ status ......................................................... 42-45
Figure 28. Approximate range of Emperor goose and tundra swan populations in
North America ....................................................................................................................... 46
Figure 29. Indices to tundra swan populations’ status...................................................................... 46
4
STATUS OF DUCKS
Abstract: In the Waterfowl Breeding Population and Habitat Survey traditional survey area (strata 1-18, 20-50,
and 75-77), the total duck population estimate was 36.2 ± 0.6 [SE] million birds. This was 14% greater
than last year’s estimate of 31.7 ± 0.6 million birds and 9% above the 1955-2005 long-term average.
Mallard (Anas platyrhynchos) abundance was 7.3 ± 0.2 million birds, which was similar to last year’s
estimate of 6.8 ± 0.3 million birds and to the long-term average. Blue-winged teal (A. discors) abundance
was 5.9 ± 0.3 million birds. This value was 28% greater than last year’s estimate of 4.6 ± 0.2 million birds
and 30% above the long-term average. The estimated abundance of green-winged teal (A. crecca; 2.6 ±
0.2 million) was 20% greater than last year and 39% above the long-term average. The estimated
number of gadwall (A. strepera; 2.8 ± 0.2 million) was 30% greater than last year and was 67% above the
long-term average, and the estimated number of redheads (Aythya americana; 0.9 ± 0.1 million)
increased 55% relative to 2005 and was 47% above the long-term average. The canvasback estimate
(A. valisineria; 0.7 ± 0.1 million) was 33% higher than last year’s and was 23% higher than the long-term
average. The Northern shoveler (Anas clypeata; 3.7 ± 0.2 million) estimate was similar to last year’s, and
69% above the long-term average. Although estimates for most species increased relative to last year
and were greater than their long-term averages, American wigeon (A. americana; 2.2 ± 0.1 million) and
scaup (Aythya affinis and A. marila combined; 3.2 ± 0.2 million) estimates were unchanged relative to
2005, but remained 17% and 37% below their long-term averages, respectively. The estimate for scaup
was a record low for the second consecutive year. The Northern pintail (Anas acuta; 3.4 ± 0.2 million)
estimate was 18% below its 1955-2005 average, although this year’s estimate was 32% greater than that
of last year. The total May pond estimate (Prairie Canada and U.S. combined) was 6.1 ± 0.2 million
ponds. This was 13% greater than last year’s estimate of 5.4 ± 0.2 million and 26% higher than the long-term
average of 4.8 ± 0.1 million ponds. The 2006 estimate of ponds in Prairie Canada was 4.4 ± 0.2
million ponds, a 13% increase from last year’s estimate of 3.9 ± 0.2 million ponds and 32% above the
1955-2005 average. The 2006 pond estimate for the north-central U.S. (1.6 ± 0.1 million) was similar to
last year’s estimate and to the long-term average. The projected mallard fall flight index was 9.8 ± 0.1
million, similar to the 2005 estimate of 9.3 ± 0.1 million birds. The eastern survey area was restratified in
2005, and is now composed of strata 51-72. Mergansers (red-breasted [Mergus serrator], common [M.
merganser], and hooded [Lophodytes cucullatus;]), mallards, American black ducks (A. rubripes), Ring-necked
ducks (Aythya collaris), goldeneyes (common [Bucephala clangula] and Barrow’s [B. islandica])
and green-winged teal were all similar to their 2005 estimates. American wigeon (-51%) and buffleheads
([B. albeola], -58%) were lower than their 2005 estimates. None of the species in the eastern survey area
differed from long-term averages.
This section summarizes the most recent
information about the status of North American duck
populations and their habitats in order to facilitate
development of harvest regulations in the U.S. The
U.S. Fish and Wildlife Service and its partners
conduct a variety of surveys to collect information on
ducks. The annual status of these populations is
assessd using databases resulting from these
surveys, which include estimates of the size of
breeding populations, production, and harvest. This
report details abundance estimates and production
outlooks; harvest survey results are discussed in
separate reports. The data and analyses were the
most current available when this report was written.
Future analyses may yield slightly different results as
databases are updated and new analytical
procedures become available.
METHODS
Breeding Population and Habitat Survey
Federal, provincial, and state agencies conduct
surveys each spring to estimate the size of breeding
populations and to evaluate habitat conditions.
These surveys are conducted using fixed-wing
aircraft and helicopters, and cover over 2.0 million
square miles that encompass principal breeding
areas of North America. The traditional survey area
(strata 1-18, 20-50, and 75-77) comprises parts of
Alaska, Canada, and the northcentral U.S., and
includes approximately 1.3 million square miles
(Appendix C). The eastern survey area (strata 51-
72) includes parts of Ontario, Quebec, Labrador,
Newfoundland, Nova Scotia, Prince Edward Island,
New Brunswick, New York, and Maine, covering an
area of approximately 0.7 million square miles.
In Prairie and Parkland Canada and the north-central
U.S., aerial waterfowl counts are corrected
5
annually for visibility bias by conducting ground
counts. In the northern portions of the traditional
survey area and the eastern survey area, duck
estimates are adjusted using visibility correction
factors derived from a comparison of airplane and
helicopter counts. Annual estimates of duck
abundance are available since 1955 for the
traditional survey area and since 1996 for all
strata (except 57-59, 69) in the eastern survey
area. However, portions of the eastern survey
area have been surveyed since 1990. In the
traditional survey area, estimates of pond
abundance in Prairie Canada are available since
1961 and in the northcentral U.S. since 1974.
Several provinces and states also conduct
breeding waterfowl surveys using various
methods; some have survey designs that allow
calculation of measures of precision for their
estimates. Information about habitat conditions
was supplied primarily by biologists working in the
survey areas. However, much ancillary weather
information was obtained from agricultural and
weather internet sites (see references). Unless
otherwise noted, z-tests were used for assessing
statistical significance, with alpha levels (P-value)
set at 0.1; actual P-values are given in tables
along with wetland and waterfowl estimates.
Since 1990 the U.S. Fish and Wildlife Service
(USFWS) has conducted aerial transect surveys
using fixed-wing aircraft in eastern Canada and
the northeast U.S., similar to those used in the
mid-continent, for estimating waterfowl
abundance. Additionally, the Canadian Wildlife
Service (CWS) has conducted a helicopter-based
aerial plot survey in core American black duck
breeding regions of Ontario, Quebec, and the
Atlantic Provinces. Historically, data from these
surveys were analyzed separately, despite
geographic overlap in survey coverage. In 2004,
the USFWS and CWS agreed to integrate the two
surveys, produce composite estimates from both
sets of survey data, and expand the geographic
scope of the survey in eastern North America.
As a result, as of 2005, waterfowl population
estimates for eastern North America are no longer
produced solely on the basis of USFWS-collected
data, but are be based on both USFWS and CWS
data. Estimates of populations in eastern North
America (strata 51-72) are now derived as
composite estimates based on data from the CWS
and USFWS surveys. For strata containing both
CWS and USFWS data (51, 52, 63, 64, 66, and
68), visibility-adjusted USFWS data were
combined with plot data; single survey results
were used as the estimates for strata containing
only one source of information (53, 54, 55, 56, 57,
58, 59, 62, 65, and 69 for transects; 70, 71, and
72 for plots). In cases where the USFWS has
traditionally not recorded observations to the
species level (i.e., scoters [Melanitta spp.],
mergansers, goldeneyes), only CWS plot survey
data were used in estimation. While estimates
were generated for all strata in the eastern survey
area, survey-wide composite estimates for this
region (Table 13) currently correspond only to
strata 51, 52, 63, 64, 66, 67, 68, 70, 71, and 72.
These strata are coincident with the geographic
extent of the CWS helicopter plot survey. In future
reports, survey-wide composite estimates will be
derived for the entire region encompassed by the
USFWS and CWS surveys (strata 51-72).
For widely-distributed species, (American black
ducks, mallards, green-winged teal, and ring-necked
duck), composite estimates of population
size were constructed using a hierarchical model,
in which change is modeled using a log-linear
model that includes survey and transect/plot
effects (e.g., Link and Sauer 2002). Area-weighted,
exponentiated year effects were
calculated using the log-linear model for each
survey, then averaged between surveys to provide
estimates of total indicated birds in each stratum.
For all other species, which occur at lower
densities and are more patchily distributed in the
eastern survey area, this modeling approach was
not suitable, and estimates for these species
represent averages of visibility-adjusted FWS and
CWS survey results.
To produce a consistent index for American
black ducks, total indicated birds were calculated
using the CWS method of scaling observed pairs.
Observed black duck pairs were scaled by 1.5
rather than the 1.0 scaling traditionally applied by
the USFWS. The CWS scaling is based on sex-specific
observations collected during the CWS
survey in eastern Canada which indicate that
approximately 50% of black duck pair
observations are actually 2 drakes. For other
species, the standard USFWS definition of total
indicated birds was used.
Changes in indices, procedures, geographic
stratification, and in the area sampled by
composite surveys, result in changes in the
estimated population totals; therefore, survey
results for eastern North America presented in this
report are not directly comparable to results
presented in previous reports. We anticipate
additional refinements to the survey design and
analysis for eastern North America during the
coming years, and composite estimates are
subject to change in the future.
6
Production and Habitat Survey
For the past three years, we have had no
traditional July Production and Habitat Survey to
verify the early predictions of our biologists in the
field, due to severe budget constraints within the
migratory bird program. However, the pilot-biologists
responsible for several survey areas (southern
Alberta, southern Saskatchewan, the Dakotas, and
Montana) returned in early July for a brief flight over
representative portions of their survey areas as a
rough assessment of habitat changes since May and
resultant duck production. This information, along
with reports from local biologists in the field, helped
formulate an overall perspective on duck production
this year.
Total Duck Species Composition
In the traditional survey area, our estimate of total
ducks excludes scoters, eiders (Somateria and
Polysticta spp.), long-tailed ducks (Clangula
hyemalis), mergansers, and wood ducks (Aix
sponsa), because the traditional survey area does
not include a large portion of their breeding range.
Mallard Fall-flight Index
The mallard fall-flight index is a prediction of the
size of the fall abundance of mallards originating
from the mid-continent region of North America.
For management purposes, the mid-continent
population is composed of mallards originating
from the traditional survey area, as well as
Michigan, Minnesota, and Wisconsin. The index is
based on the mallard models used for Adaptive
Harvest Management, and considers breeding
population size, habitat conditions, adult summer
survival, and projected fall age ratio (young/adult).
The projected fall age ratio is predicted from a
model that depicts how the age ratio varies with
changes in spring population size and pond
abundance. The fall-flight index represents a
weighted average of the fall flights predicted by
the four alternative models of mallard population
dynamics used in Adaptive Harvest Management
(U. S. Fish and Wildlife Service 2006).
RESULTS AND DISCUSSION
2005 in Review
Habitat conditions at the time of the survey in
May 2005 were variable, with some areas
improved relative to 2004 and others that
remained or became increasingly dry. The total
May pond estimate (Prairie and Parkland Canada
and the northcentral U.S. combined) was 5.4 ± 0.2
million ponds, which was 37% greater than the
2004 estimate of 3.9 ± 0.2 million ponds, and 12%
higher than the long-term average of 4.8 ± 0.1
million ponds. Habitat in the surveyed portion of
the U.S. prairies was in fair to poor condition due
to a dry fall, winter, and early spring and warm
winter temperatures. Nesting habitat was
particularly poor in South Dakota because below-average
precipitation resulted in degraded
wetland conditions and increased tilling and
grazing of wetland margins. Birds likely over-flew
the state for wetter conditions further north. Water
levels, wetland conditions, and upland nesting
cover in North Dakota and eastern Montana
improved markedly during June, following the
survey, with the onset of well-above average
precipitation.
The 2005 pond estimate for north-central U.S.
(1.5 ± 0.1 million) was similar to the 2004
estimate. The prairies of southern Alberta and
southwestern Saskatchewan were also quite dry
in early May of 2005. The U.S. and Canadian
prairies received substantial rain in late May and
during the entire month of June that recharged
wetlands and encouraged growth of vegetation.
While this improved habitat quality on the Prairies,
it came too late to benefit early-nesting species,
but likely did benefit late nesting species and
renesting efforts. Record high rains flooded the
lower elevation prairie areas of central Manitoba
during April 2005, which produced fair or poor
nesting conditions for breeding waterfowl. In
contrast, the Canadian Parklands were much
improved relative to 2004, due to several years of
improving nesting cover and above-normal
precipitation the previous fall and winter. These
areas were in good-to-excellent condition at the
start of the survey and remained so into July.
Overall, the May pond estimate in Prairie and
Parkland Canada was 3.9 ± 0.2 million in 2005,
which was a 56% increase over the 2004 estimate
of 2.5 ± 0.1 million ponds and 17% higher than the
long-term average of 3.3 ± 0.3 million ponds.
Portions of Northern Manitoba and Northern
Saskatchewan also experienced flooding during
2005, which resulted in only fair conditions for
breeding waterfowl. In contrast, most of the
Northwest Territories was in good condition due to
adequate water and a timely spring break up that
made habitat available to early-nesting species.
However, dry conditions in eastern parts of the
Northwest Territories and northern Alberta
resulted in low water levels in lakes and ponds
7
and the complete drying of some wetlands.
Therefore, habitat was also classified as fair in
these areas. For the most part, habitats in Alaska
were in excellent condition, with an early spring
and good water levels, except for a few flooded
river areas and on the North Slope, where spring
was late.
In the Eastern Survey area (strata 51-72),
habitat conditions were generally good during
2005 due to adequate water and relatively mild
spring temperatures. Exceptions were the coast
of Maine and the Atlantic Provinces, where May
temperatures were cool and some flooding
occurred along the coast and major rivers. Also,
below-normal precipitation left some habitat in fair
to poor condition in southern Ontario. However,
precipitation in southern Ontario after survey
completion improved habitat conditions in that
region.
In the traditional survey area, the 2005 total
duck population estimate (excluding scoters,
eiders, long-tailed ducks, mergansers, and wood
ducks) was 31.7 ± 0.6 million birds, similar to the
2004 estimate of 32.2 ± 0.6 million birds, and 5%
below the long-term (1955-2004) average. In the
eastern Dakotas, total duck numbers were 14%
below their 2004 estimate, but remained 10%
above the long-term average. Counts in southern
Alberta were 27% higher than the previous year’s,
but remained 26% below the long-term average.
The total-duck estimate increased 38% relative to
2004 in southern Saskatchewan and was 9%
above the long-term average. Total duck
estimates in central and northern Alberta,
northeastern British Columbia and the Northwest
Territories were 20% below the 2004 estimate and
35% below the long-term average. Counts in the
northern Saskatchewan—northern Manitoba--
western Ontario area, and the western Dakotas--
Eastern Montana survey areas were 21% and
20% below 2004 estimates, respectively, and 10%
and 20% below their long-term averages. In the
Alaska--Yukon Territory--Old Crow Flats region
the total duck estimate was similar to that of 2004,
but remained 45% above its long-term average.
Total duck counts in southern Manitoba remained
unchanged from the 2004 estimate and the long-term
average
Several states and provinces conduct breeding
waterfowl surveys in areas outside the geographic
extent of the Waterfowl Breeding Population and
Habitat Survey of the USFWS and CWS. In British
Columbia, California, the northeastern U.S., Oregon,
and Wisconsin, measures of precision for survey
estimates are available. Total duck abundance
increased by 49% in California relative to 2004, and
was similar to 2004 in British Columbia, Wisconsin,
and the northeastern U.S. The total duck estimate
was similar to the long-term average in California. In
Wisconsin, total ducks were 73% above their long-term
average. In British Columbia, California, and the
northeastern U.S., total duck estimates were similar
to their long-term averages. Of the states without
measures of precision for total duck numbers,
estimates of total ducks decreased in Nevada,
Minnesota, Washington, Oregon, and Michigan, and
increased in Nevada, relative to 2004.
Weather and habitat conditions during the
summer months can influence waterfowl
production. Good wetland conditions increase
renesting effort and brood survival. In general,
2005 habitat conditions improved over most of the
traditional survey area between May and July of
2005. Habitat in most of the prairies, especially
southern Saskatchewan and eastern Montana
improved between May and July because of
abundant summer rain. Habitat conditions in the
northern and eastern areas tend to be more stable
because of the deeper, more permanent water
bodies there. In general, the outlook for production
was rated fair to good in the northern Prairie
Provinces and good to excellent in the eastern
survey area during 2005.
2006 Breeding Habitat Conditions,
Populations, and Production
Overall Habitat and Population Status
Despite a very warm winter, breeding waterfowl
habitat quality in the U.S. and Canada is slightly
better this year than last year. Improvements in
Canadian and U.S. prairie habitats were primarily
due to average to above-average precipitation,
warm spring temperatures, and carry-over effects
from the good summer conditions of 2005.
Improved habitat conditions were reflected in the
higher number of ponds counted in Prairie
Canada this year compared to last year. The
2006 estimate of ponds in Prairie Canada was 4.4
± 0.2 million ponds, a 13% increase from last
year’s estimate of 3.9 ± 0.2 million ponds, and
32% above the 1955-2005 average (Table 1,
Figure 1). The parkland and northern grassland
regions of Manitoba and Saskatchewan received
abundant rain in March and April, which created
good to excellent habitat conditions. Higher water
tables prevented farm activities in wetland basins
and excellent residual nesting cover remained
around many potholes. Many wetlands flooded
beyond their normal basins and into surrounding
uplands. Deeper water in permanent and semi-
8
Table 1. Estimated number (in thousands) of May ponds in portions of prairie and parkland Canada and the northcentral U.S.
Change from 2005 Change from LTA
Survey area 2006 2005 % P LTA a % P
Prairie Canada
S. Alberta 996 750 +33 0.020 722 +38 <0.001
S. Saskatchewan 2,719 2,415 +13 0.250 1,963 +38 <0.001
S. Manitoba 735 755 -3 0.805 673 +9 0.351
Subtotal 4,450 3,921 +13 0.074 3,358 +32 <0.001
Northcentral U.S.
Montana and Western Dakotas 615 663 -7 0.512 528 +16 0.064
Eastern Dakotas 1,030 798 +29 0.011 994 +4 0.625
Subtotal 1,644 1,461 +13 0.116 1,522 +8 0.159
Grand total 6,094 5,381 +13 0.025 4,830 +26 <0.001
aLong-term average. Prairie and parkland Canada, 1961-2005; northcentral U.S. and grand total, 1974-2005.
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Millions
Northcentral U.S.
Prairie Canada
Total
Year
Figure 1. Number of ponds in May and 90% confidence intervals in prairie Canada and the northcentral U.S.
9
permanent wetlands, coupled with increased
amounts of flooded emergent vegetation and
woodland, likely benefited diving ducks and
overwater- and cavity-nesting species. However,
spring precipitation in the grasslands of southern
Saskatchewan and extreme southwestern
Manitoba was insufficient to fill seasonal and
semi-permanent wetlands or create temporary
wetlands for waterfowl, leaving these regions in
fair or poor condition at the time of the survey.
Above-average precipitation in the fall and spring
in parts of southern Alberta improved conditions in
this historically important pintail breeding region.
This region has been dry since 1998, with the
exception of 2003. However, central Alberta
remained dry.
Habitat conditions on the U.S prairies were
more variable than those on the Canadian
prairies. The 2006 pond estimate for the north-central
U.S. (1.6 ± 0.1 million) was similar to last
year’s estimate and the long-term average. The
total pond estimate (Prairie Canada and U.S.
combined) was 6.1 ± 0.2 million ponds. This was
13% greater than last year’s estimate of 5.4 ± 0.2
million and 26% higher than the long-term
average of 4.8 ± 0.1 million ponds. Habitat quality
improved minimally in the easternmost regions of
North and South Dakota relative to 2005. Small
areas of the Eastern Dakotas were in good-to-excellent
condition, helped by warm April
temperatures and spring rains that advanced
vegetation growth by about 2 weeks. However,
most of the Drift Prairie, the Missouri Coteau, and
the Coteau Slope remained in fair to poor
condition due to lack of temporary and seasonal
water and the deteriorated condition of semi-permanent
basins. Permanent wetlands and
dugouts were typically in various stages of
recession. The Western Dakotas were generally
in fair condition. Most wetland and upland
habitats in Montana benefited modestly from
average to above-average fall and winter
precipitation and subsequent improvement in
nesting habitat last year. Spring precipitation in
Montana during March and April also helped
mitigate several years of drought. Much of central
Montana was in good condition due to ample late
winter and early spring precipitation. Biologists
there also noted improvements in upland
vegetation over recent years. In the central
region, most pond basins were full and stream
systems were flowing. However, nesting habitat
was generally fair to poor for most of the northern
portion of Montana.
Habitat conditions in most northern regions of
Canada were improved over last year due to an
early ice break-up, warm spring temperatures, and
good precipitation levels. In northern
Saskatchewan, northern Manitoba, and western
Ontario, winter snowfall was sufficient to recharge
most beaver ponds and small lakes. Larger lakes
and rivers tended to have higher water levels than
in recent years. Conditions in the smaller
wetlands were ideal. However, in northern
Manitoba and northern Saskatchewan, some
lakes associated with major rivers were flooded,
with some flooded well into the surrounding
upland vegetation. The potential for habitat loss
due to flooding caused biologists to classify this
region as good. In Alberta, water levels improved
to the north, except for the Athabasca Delta,
where wetlands, especially seasonal wetlands,
generally had low water levels. Most of the
Northwest Territories had good water levels. The
exceptions were the southern portion, where
heavy May rains flooded some nesting habitat, as
well as a dry swath across the central part of the
province. In contrast to most other northern areas
and to the past few years, spring did not arrive
early in Alaska this year. Overall, a normal spring
phenology occurred throughout most of Alaska
and the Yukon Territory, and ice persisted late in
the following regions: the outer coast of the Yukon
Delta, the northern Seward Peninsula, and on the
Old Crow Flats. Some flooding occurred on a few
major rivers. Overall, good waterfowl production
was anticipated this year from the northwestern
continental area, contingent on continued
seasonal temperatures.
Spring-like conditions also arrived early in the
East, with an early ice break-up and relatively mild
temperatures. Biologists reported that habitat
conditions were generally good across most of the
survey area. Most regions had a warm, dry winter
and a dry early spring. Extreme southern Ontario
was relatively dry during the survey period and
habitats were in fair to poor condition. However,
precipitation after survey completion improved
habitat conditions in this region. Abundant rain in
May improved water levels in Maine, the
Maritimes, southern Ontario, and Quebec, but
caused some flooding in southern Ontario and
Quebec and along the coast of Maine, New
Brunswick, and Nova Scotia. In Quebec, a very
early spring assured good habitat availability.
Despite the early spring and the abundance of
spring precipitation, a dry winter still left most of
the marshes and rivers drier than in recent years.
Many bogs were noticeably drier than recent
years or dry entirely in a few cases. Winter
precipitation increased to the west and north,
which resulted in generally good water levels in
10
central and northern Ontario. Conditions were
good to excellent in central and northern Ontario
due to the early spring phenology, generally good
water levels, and warm spring temperatures.
In the traditional survey area, the total duck
population estimate (excluding scoters, eiders,
long-tailed ducks, mergansers, and wood ducks)
was 36.2 ± 0.6 [SE] million birds. This was 14%
greater than last year’s estimate of 31.7 ± 0.6
million birds and 9% above the 1955-2005 long-term
average (Table 2, Appendix G).
In the eastern Dakotas, total duck numbers
were 12% higher than last year’s estimate, and
23% above the long-term average. Counts in
southern Alberta were 44% higher than last
year’s, and similar to their long-term average. The
total-duck estimate increased 27% relative to last
year in southern Saskatchewan and was 37%
above the long-term average. The total duck count
in southern Manitoba was similar to the 2005
estimate, but 16% above its long-term average.
The total duck estimate in central and northern
Alberta, northeastern British Columbia and the
Northwest Territories was similar to that of 2005,
and 28% below the long-term average (Table 2).
The estimate in the northern Saskatchewan—
northern Manitoba--western Ontario area was
16% below that of 2005, and 24% below the long-term
average. Total ducks in the western
Dakotas--Eastern Montana area were 48% above
their 2005 estimate, and 18% above their long-term
average. In the Alaska--Yukon Territory--Old
Crow Flats region the total duck estimate was
similar to that of 2005, but remained 34% above
its long-term average.
Several states and provinces conduct breeding
waterfowl surveys in areas outside the geographic
extent of the Waterfowl Breeding Population and
Habitat Survey of the USFWS and CWS. In British
Columbia, California, the northeastern U.S., Oregon,
and Wisconsin, measures of precision for survey
estimates are available. Total duck estimates in
California and the northeastern U.S. were similar to
those of 2005 and to long-term averages. In Oregon,
the total duck estimate was 17% higher than last
year’s, but 17% lower than the long-term average. In
British Columbia, total duck numbers did not differ
from their 2005 estimate, or their long-term average.
In Wisconsin, the total duck estimate was 28% below
last year’s, but remained 22% above the long-term
average. Of the states without measures of precision
for total duck numbers, estimates of total ducks
decreased in Minnesota and Michigan relative to
2005.
Trends and annual breeding population
estimates for 10 principal duck species from the
traditional survey area are provided in Figure 2,
Tables 3-12, and Appendix F. Mallard abundance
was 7.3 ± 0.2 million, which is similar to last year’s
estimate of 6.8 ± 0.3 million, and to the long-term
average (Table 3). Mallard numbers were up 34%
in southern Alberta relative to 2005, but remained
18% below the long-term average. In the
Montana-Western Dakotas survey area, mallard
counts were 76% higher than in 2005, and 36%
higher than the long-tem mean. Mallard estimates
were similar to 2005 estimates in the central and
northern Alberta--northeastern British Columbia--
Northwest Territories region, as well as the
northern Saskatchewan--northern Manitoba--
western Ontario survey area, but remained 49%
and 43% below their long-term averages,
respectively. Mallard numbers fell 27% since
2005, but remained 44% above their long-term
average in the Alaska--Yukon Territory--Old Crow
Flats region. In southern Manitoba and in the
Eastern Dakotas, mallard counts were similar to
last year’s, but were 35% and 92% above their
long-term averages, respectively. The mallard
estimate was similar to last year’s count, and 12%
below the long-term average in southern
Saskatchewan. In other areas where surveys are
conducted and measures of precision for estimates
are provided (the same states as for total ducks, as
well as Michigan and Minnesota), mallard abundance
remained unchanged from 2005, except for
Minnesota (-33%) and Wisconsin (-31%). Mallard
estimates were below the long-term average in
Michigan (-50%), Oregon (-20%), and British
Columbia (-26%), and similar to long-term averages
in California, the northeastern U. S., and Wisconsin.
Minnesota mallards were 28% below their long-term
average, but a test statistic for this estimate was
unavailable.
Blue-winged teal abundance was estimated at
5.9 ± 0.3 million birds, 28% higher than last year’s
estimate of 4.6 ± 0.2 million birds and 30% higher
than the 1955-2005 average. Of the other duck
species, gadwall (2.8 ± 0.2 million) were 30%
higher than their 2005 estimate, and were 67%
above their long-term average. American wigeon
(2.2 ± 0.1 million) and scaup (3.2 ± 0.2 million)
were similar to their 2005 estimates, but were
17% and 37% below their long-term averages,
respectively. The green-winged teal (2.6 ± 0.2
million) estimate was 20% higher than last year’s,
and 39% higher than the long-term average.
Northern pintails (3.4 ± 0.2 million) increased by
32% relative to last year, but remained 18% below
their long-term average. The Northern shoveler
(3.7 ± 0.2 million) estimate was similar to last
year’s, and 69% above the long-term average.
11
Table 2. Total ducka breeding population estimates (in thousands).
Change from 2005 Change from LTA
Region 2006 2005 % P LTAb % P
Traditional survey area
Alaska - Yukon Territory
- Old Crow Flats 4,755 5,114 -7 0.149 3,550 +34 <0.001
C. & N. Alberta - N.E. British Columbia
- Northwest Territories 5,132 4,713 +9 0.222 7,153 -28 <0.001
N. Saskatchewan - N. Manitoba
- W. Ontario 2,711 3,223 -16 0.047 3,557 -24 <0.001
S. Alberta 4,581 3,178 +44 <0.001 4,283 +7 0.121
S. Saskatchewan 10,096 7,967 +27 <0.001 7,348 +37 <0.001
S. Manitoba 1,796 1,627 +10 0.137 1,544 +16 0.003
Montana and Western Dakotas 1,910 1,290 +48 <0.001 1,613 +18 0.001
Eastern Dakotas 5,181 4,623 +12 0.073 4,201 +23 <0.001
Total 36,160 31,735 +14 <0.001 33,251 +9 <0.001
Other regions
British Columbia c 8 6 +40 0.252 6 +22 0.385
California 649 615 +6 0.719 599 -8 0.507
Northeastern U.S. d 1,392 1,416 -2 0.865 1,429 -3 0.719
Oregon 263 225 +17 0.061 295 -11 0.016
Wisconsin 523 724 -28 0.022 429 +22 0.072
a Excludes eider, long-tailed duck, wood duck, scoter, and merganser in traditional survey area; excludes eider, long-tailed duck, wood duck, redhead, canvasback and ruddy
duck in eastern survey area; species composition for other regions varies.
b Long-term average. Traditional survey area 1955-2005; years for other regions vary (see Appendix E).
c Index to waterfowl use in prime waterfowl producing regions of the province.
d Includes all or portions of CT, DE, MD, MA, NH, NJ, NY, PA, RI, VT, and VA.
12
Table 3. Mallard breeding population estimates (in thousands).
Change from 2005 Change from LTA
Region 2006 2005 % P LTAb % P
Traditional survey area
Alaska - Yukon Territory
- Old Crow Flats 516 703 -27 0.009 357 +44 0.001
C. & N. Alberta - N.E. British Columbia
- Northwest Territories 558 533 +5 0.818 1,086 -49 <0.001
N. Saskatchewan - N. Manitoba
- W. Ontario 656 937 -30 0.116 1,159 -43 <0.001
S. Alberta 901 671 +34 0.006 1,099 -18 <0.001
S. Saskatchewan 1,832 1,729 +6 0.530 2,072 -12 0.021
S. Manitoba 511 455 +12 0.351 378 +35 0.004
Montana and Western Dakotas 679 387 +76 <0.001 499 +36 0.002
Eastern Dakotas 1,624 1,340 +21 0.140 846 +92 <0.001
Total 7,277 6,755 +8 0.147 7,496 -3 0.338
Eastern survey area 371 402 -7 b 364 +1 b
Other regions
British Columbia c <1 <1 -6 0.688 <1 -26 <0.001
California 399 318 +26 0.270 372 -7 0.667
Michigan 208 230 -10 0.630 414 -50 <0.001
Minnesota 161 239 -33 0.038 223 -28 e
Northeastern U.S. d 725 754 -4 0.693 800 -9 0.136
Oregon 88 83 +6 0.598 110 -20 0.003
Wisconsin 219 317 -31 0.064 179 +22 0.193
a Long-term average. Traditional survey area 1955-2005; eastern survey area 1990-2005; years for other regions vary (see Appendix E).
b P-values not appropriate because these data were analyzed with Bayesian methods.
c Index to waterfowl use in prime waterfowl producing regions of the province.
d Includes all or portions of CT, DE, MD, MA, NH, NJ, NY, PA, RI, VT, and VA.
e Value for test statistic was not available.
13
Figure 2. Breeding population estimates, 90% confidence intervals, and North American Waterfowl Management
Plan population goal (dashed line) for selected species in the traditional survey area (strata 1-18, 20-50, 75-77).
Mallard
0
2
4
6
8
10
12
14
1955 1965 1975 1985 1995 2005
Year
Millions
American wigeon
0
1
2
3
4
5
1955 1965 1975 1985 1995 2005
Year
Millions
Gadwall
0
1
2
3
4
5
1955 1965 1975 1985 1995 2005
Year
Millions
Blue-winged teal
0
1
2
3
4
5
6
7
8
9
1955 1965 1975 1985 1995 2005
Year
Millions Green-winged teal
0
1
2
3
4
1955 1965 1975 1985 1995 2005
Year
Millions
Total ducks
20
25
30
35
40
45
50
1955 1965 1975 1985 1995 2005
Year
Millions
14
Figure 2 (continued).
Northern pintail
0
2
4
6
8
10
12
1955 1965 1975 1985 1995 2005
Year
Millions
Canvasback
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1955 1965 1975 1985 1995 2005
Year
Millions
Redhead
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1955 1965 1975 1985 1995 2005
Year
Millions
Scaup
0
2
4
6
8
10
1955 1965 1975 1985 1995 2005
Year
Millions
Northern shoveler
0
1
2
3
4
5
1955 1965 1975 1985 1995 2005
Year
Millions
American black duck
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1955 1965 1975 1985 1995 2005
Year
Millions
Mississippi Flyway
Atlantic Flyway
Total
15
Redhead (0.9 ± 0.1 million), and canvasback (0.7
± 0.1 million) estimates were 55% and 33% above
their 2005 estimates and 47% and 23% above
long-term averages, respectively.
Populations of the 10 most abundant species in
the eastern survey area were all similar to their
1990-2005 estimates (Table 13, Figures 3 and 4,
Appendix H). American wigeon and buffleheads
were 51% and 58% below their 2005 estimates,
respectively. Estimates of all other species in the
survey area were similar to last year’s estimates.
The longest time-series of data available to assess
the status of the American black duck (Anas
rubripes) is provided by the midwinter surveys
conducted in January in states of the Atlantic and
Mississippi Flyways. The trend in the winter index for
the total population is depicted in Figure 2. Measures
of precision are not available for the midwinter
surveys. Midwinter counts of American black ducks
(214,800) in both flyways combined) increased 5%
relative to 2005 counts (203,900), but remained 18%
lower than the 10-year mean (261,700). In the
Atlantic Flyway, the midwinter index of 190,700
increased 4% from 184,100 in 2005, and was 14%
below the most recent 10-year mean (221,500). In
the Mississippi Flyway, the American black duck mid-winter
index increased 22% from 19,900 in 2005 to
24,200, which is 40% below the 10-year mean
(40,300). A shorter time series for assessing change
in American black duck population status is provided
by the breeding waterfowl surveys conducted by the
USFWS and CWS in the eastern survey area. In the
eastern survey area, the 2005 estimate for breeding
American black ducks (490,000) was similar to the
2005 estimate (472,000) and to the 1990-2005
average (458,000).
Trends in wood duck populations are monitored by
the North American Breeding Bird Survey (BBS), a
series of roadside routes surveyed during May and
June each year. Wood ducks are encountered with
low frequency along BBS routes, limiting the amount
and quality of available information for analysis
(Sauer and Droege 1990). However, the BBS
provides the only long-term indices of this species'
regional populations. Trend analysis suggests that
wood duck numbers have increased 3.7% per year
over the entire survey period (1966-2005) and 2.0%
over the past 20 years (1986-2005), in the Atlantic
and Mississippi Flyways combined. Specifically, for
the Atlantic Flyway, the BBS indicated a 4.6% annual
increase in wood ducks over the entire 40 years of
the survey (1966-2005), and a 2.6% annual increase
over the past 20 years (1986-2005). In the
Mississippi Flyway, the 40-year BBS trend indicated
a 3.1% annual increase, and although the slope of
the 20-year trend is positive, it is not statistically
significant. Analysis of wood duck BBS data over
the past 10-year period (1996-2005) yielded no
significant short-term trend for the Atlantic or
Mississippi Flyways, or the two flyways combined (J.
Sauer, U. S. Geological Survey/Biological Resources
Division, unpublished data).
Weather and habitat conditions during the
summer months can influence waterfowl
production. Good wetland conditions increase
renesting effort and brood survival. In general,
2006 July habitat conditions over most of the
traditional survey area were similar to those
observed in May. While no formal July surveys
were flown this year, experienced crew leaders in
Montana and the western Dakotas, the eastern
Dakotas, southern Alberta, and southern
Saskatchewan returned to their May survey areas
in early July to qualitatively assess habitat
changes between May and July. Biologists from
other survey areas communicated with local
biologists to get their impressions of 2006
waterfowl production and monitored weather
conditions. Habitat over most of the prairies
remained stable between May and July because
of adequate summer rain. The exception was the
eastern Dakotas survey area, where wetland
conditions deteriorated. Habitat conditions in the
northern and eastern areas tend to be more stable
because of the deeper, more permanent water
bodies there. In general, the outlook for production
was rated fair to good in the northern Prairie
Provinces and good to excellent in the eastern
survey area.
Regional Habitat and Population Status
A description of habitat conditions, populations,
and production for each for the major breeding areas
follows. More detailed reports of specific regions are
available in Waterfowl Population Surveys reports,
located on the Division of Migratory Bird
Management’s home page. Some of the habitat
information that follows was taken from those reports
(http://www.fws.gov/migratorybirds/reports/reports.
html).
Southern Alberta: The outlook for this crew area
(strata 26-29, 75-76) was much improved over
recent years. Precipitation during June was
generally much above normal in the southern
plains of Alberta and in the northwest corner of the
province, and below to much below normal in
north-central Alberta. Precipitation elsewhere was
generally below normal to normal.
16
Figure 3. Breeding population estimates (from Bayesian hierarchical models) and 95% credibility intervals for selected
species in the eastern survey area (strata 51, 52, 63, 64, 66-68, 70-72).
Mallard
0
100000
200000
300000
400000
500000
600000
700000
800000
1990 1995 2000 2005
Year
American black duck
0
100000
200000
300000
400000
500000
600000
700000
1990 1995 2000 2005
Year
Green-winged teal
0
100000
200000
300000
400000
1990 1995 2000 2005
Year
Ring-necked duck
0
100000
200000
300000
400000
500000
600000
700000
800000
1990 1995 2000 2005
Year
17
Figure 4. Breeding population estimates (harmonic means) and 95% confidence intervals for selected species in the
eastern survey area (strata 51, 52, 63, 64, 66-68, 70-72).
American wigeon
0
10000
20000
30000
1990 1995 2000 2005
Year
Scaup
0
20000
40000
60000
80000
100000
120000
1990 1995 2000 2005
Year
Goldeneyes
0
100000
200000
300000
400000
500000
600000
1990 1995 2000 2005
Year
Scoters
0
100000
200000
300000
400000
500000
600000
700000
1990 1995 2000 2005
Year
Bufflehead
0
10000
20000
30000
40000
50000
60000
70000
1990 1995 2000 2005
Year
Mergansers
0
100000
200000
300000
400000
500000
600000
700000
1990 1995 2000 2005
Year
18
Table 4. Gadwall breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 2 3 -29 0.739 2 0 0.998
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 135 77 +75 0.102 47 +187 0.006
N. Saskatchewan- N. Manitoba
- W. Ontario 16 19 -14 0.747 27 -41 0.042
S. Alberta 455 338 +35 0.152 309 +47 0.010
S. Saskatchewan 1,202 723 +66 0.006 556 +116 <0.001
S. Manitoba 125 120 +4 0.820 67 +88 <0.001
Montana and Western Dakotas 216 187 +16 0.474 194 +11 0.476
Eastern Dakotas 673 712 -6 0.642 491 +37 <0.001
Total 2,825 2,179 +30 0.003 1,692 +67 <0.001
Table 5. American wigeon breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 822 873 -6 0.552 511 +61 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 570 583 -2 0.921 912 -38 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario 105 174 -40 0.080 253 -58 <0.001
S. Alberta 189 125 +50 0.025 296 -36 <0.001
S. Saskatchewan 282 294 -4 0.845 425 -34 <0.001
S. Manitoba 16 34 -53 0.086 62 -74 <0.001
Montana and Western Dakotas 120 67 +79 0.008 109 +10 0.531
Eastern Dakotas 67 73 -8 0.767 48 +39 0.140
Total 2,171 2,225 -2 0.766 2,617 -17 <0.001
19
Table 6. Green-winged teal breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 780 713 +9 0.471 358 +118 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 751 437 +72 0.018 752 0 0.990
N. Saskatchewan- N. Manitoba
- W. Ontario 303 310 -2 0.896 197 +54 0.001
S. Alberta 178 159 +12 0.720 194 -8 0.709
S. Saskatchewan 401 359 +12 0.632 230 +75 0.007
S. Manitoba 65 55 +19 0.448 52 +27 0.215
Montana and Western Dakotas 34 83 -59 0.005 40 -15 0.364
Eastern Dakotas 75 42 +81 0.164 45 +67 0.164
Total 2,587 2,157 +20 0.031 1,867 +39 <0.001
Table 7. Blue-winged teal breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 0 3 -100 0.339 1 -100 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 316 247 +28 0.456 270 +17 0.515
N. Saskatchewan- N. Manitoba
- W. Ontario 82 139 -41 0.237 265 -69 <0.001
S. Alberta 864 649 +33 0.126 609 +42 0.015
S. Saskatchewan 2,228 1,597 +40 0.019 1,218 +83 <0.001
S. Manitoba 426 339 +26 0.117 382 +11 0.329
Montana and Western Dakotas 346 286 +21 0.240 263 +32 0.047
Eastern Dakotas 1,598 1,325 +21 0.171 1,492 +7 0.418
Total 5,860 4,586 +28 0.001 4,501 +30 <0.001
20
Table 8. Northern shoveler breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 409 666 -39 0.003 267 +53 0.002
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 193 213 -10 0.690 213 -10 0.498
N. Saskatchewan- N. Manitoba
- W. Ontario 12 29 -59 0.016 43 -72 <0.001
S. Alberta 701 548 +28 0.190 360 +95 <0.001
S. Saskatchewan 1,612 1,314 +23 0.210 648 +149 <0.001
S. Manitoba 178 211 -16 0.430 107 +66 <0.001
Montana and Western Dakotas 163 148 +10 0.612 149 +9 0.514
Eastern Dakotas 414 464 -11 0.477 389 +6 0.594
Total 3,680 3,591 +2 0.765 2,177 +69 <0.001
Table 9. Northern pintail breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 1,041 905 +15 0.310 913 +14 0.174
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 126 108 +16 0.662 378 -67 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario 6 8 -31 0.470 41 -86 <0.001
S. Alberta 611 282 +116 <0.001 721 -15 0.107
S. Saskatchewan 1,024 858 +19 0.343 1,218 -16 0.203
S. Manitoba 57 68 -16 0.480 112 -49 <0.001
Montana and Western Dakotas 264 75 +252 <0.001 269 -2 0.907
Eastern Dakotas 257 256 +1 0.968 459 -44 <0.001
Total 3,386 2,561 +32 0.001 4,111 -18 <0.001
21
Table 10. Redhead breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 10 <1 +4000 0.106 1 +622 0.154
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 59 49 +19 0.679 38 +54 0.143
N. Saskatchewan- N. Manitoba
- W. Ontario 5 13 -61 0.050 28 -82 <0.001
S. Alberta 154 91 +69 0.074 116 +33 0.214
S. Saskatchewan 435 226 +93 0.007 190 +129 0.001
S. Manitoba 102 98 +4 0.903 72 +42 0.127
Montana and Western Dakotas 12 3 +315 0.054 9 +25 0.573
Eastern Dakotas 139 112 +25 0.389 169 -17 0.284
Total 916 592 +55 0.001 624 +47 0.001
Table 11. Canvasback breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 73 95 -23 0.542 91 -20 0.475
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 109 98 +12 0.771 73 +50 0.177
N. Saskatchewan- N. Manitoba
- W. Ontario 13 39 -67 0.068 55 -77 <0.001
S. Alberta 76 43 +79 0.105 64 +20 0.440
S. Saskatchewan 287 162 +76 0.026 182 +57 0.037
S. Manitoba 87 48 +84 0.166 56 +56 0.221
Montana and Western Dakotas 12 5 +157 0.121 8 +58 0.321
Eastern Dakotas 33 31 +5 0.875 33 0 1.000
Total 691 521 +33 0.051 562 +23 0.067
22
Table 12. Scaup (greater and lesser scaup combined) breeding population estimates (in thousands) for regions in the traditional
survey area.
Change from 2005 Change from LTA
Region 2006 2005 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats 884 961 -8 0.500 915 -3 0.680
C. & N. Alberta – N.E. British Columbia
- Northwest Territories 1,169 1,361 -14 0.316 2,627 -55 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario 335 349 -4 0.816 587 -43 <0.001
S. Alberta 214 127 +69 0.071 353 -39 0.001
S. Saskatchewan 391 381 +3 0.918 416 -6 0.714
S. Manitoba 97 60 +61 0.146 135 -28 0.103
Montana and Western Dakotas 19 16 +14 0.723 53 -65 <0.001
Eastern Dakotas 138 132 +5 0.854 97 +42 0.097
Total 3,247 3,387 -4 0.586 5,184 -37 <0.001
Table 13. Duck breeding population estimates a (in thousands) for the 10 most abundant species in the eastern survey area.
Species 2006 2005 % Change from
2005 Average b % Change from
average
Mergansers (common, red-breasted, and
hooded) 448 418 +7 373 +20
Mallard 371 402 -7 364 +1
American black duck 490 472 +4 458 +7
American wigeon 8 16 -51c 11 -28
Green-winged teal 223 223 <1% 219 +2
Scaup (greater and lesser) 72 14 +428 24 +198
Ring-necked duck 522 509 +2 484 +7
Goldeneyes (common and Barrow’s) 246 320 -23 285 -14
Bufflehead 10 23 -58 c 20 -51
Scoters (black and surf) 65 96 -32 86 -24
a Estimates for mallards, American black ducks, green-winged teal, and ring-necked duck from Bayesian hierarchical analysis using FWS and CWS data from strata 51,
52, 63, 64, 66-68, 70-72. All others were computed as harmonic means of FWS and CWS estimates for strata 51, 52, 63, 64, 66-68, 70-72.
b Average for 1990-2005.
c Significance (P<0.05) determined by non-overlap of Bayesian credibility intervals or confidence intervals.
23
Overall, May ponds were up 33% relative to
2005, and 38% above their long-term average. In
response, total duck (+44%) and Northern pintail
(+116%) numbers were considerably higher than
in 2005, and were similar to their long-term
averages. Mallard (+34%), American wigeon
(+50%), and scaup (+69%) estimates were much
higher than those of 2005, but these species
remained 18%, 36%, and 39% below their long-term
averages, respectively. Northern shoveler,
gadwall, and blue-winged teal estimates were all
similar to 2005 estimates, but these species were
95%, 47%, and 42% above their long-term
averages for the survey area, respectively. The
redhead estimate was 69% higher than last
year’s, but similar to its long-term average.
Green-winged teal and canvasback estimates
were similar to their 2005 counts and long-term
averages.
Precipitation during May and June was below
normal to normal, except in most southern plains
areas and some areas of northwest Alberta where
it has been above to much above normal. Habitat
conditions in July remained similar to conditions in
May. Precipitation in June kept pond levels high,
which predicted good brood production. Some
areas in eastern stratum 26 actually improved
from May to July.
Southern Saskatchewan: During the 2006 survey,
Southern Saskatchewan generally had poor to fair
waterfowl habitat in the southern grasslands and
good to excellent waterfowl habitat in the northern
grasslands and Parkland region. Spring runoff
was below average in the southwest, southeast,
and northwest and above average in the northeast
and central regions of the grainbelt. Flooding of
fields, roads, and houses occurred in May and
early June in this region.
The grasslands strata of 32 and 33 received
below average to average winter precipitation,
except in the Cypress Hills, where precipitation
was above average (Agriculture and Agri-food
Canada 2006). Spring precipitation increased
across the southern grasslands, but not to the
extent necessary to fill seasonal and semi-permanent
wetlands or create ephemeral or
temporary wetlands for waterfowl. Upland habitat
conditions throughout the southern grasslands
appeared to be in fair to good condition for nesting
ducks.
The Parklands (stratum 30-31) received
average to above average precipitation during the
winter and spring and both upland nesting cover
and wetlands were in good to excellent condition
(Agriculture and Agri-food Canada 2006). Many
wetlands flooded beyond their normal basins and
into the surrounding uplands. There was also an
increase in flooded emergent vegetation and
woodland, which likely benefited overwater and
cavity nesting species.
The May pond estimate was similar to last
year's, and was 38% above the long-term
average. Total ducks were 27% above the 2005
estimate, and 37% higher than their long-term
average. Mallard and American wigeon estimates
were similar to those of 2005, but were 12% and
34% below their long-term averages, respectively.
Northern shoveler numbers were also similar to
last year’s, but were 149% above the long-term
average. Gadwall (+66%, +116% LTA), blue-winged
teal (+40%, +83% LTA), redhead (+93%,
+129% LTA), and canvasback (+76%, +57% LTA)
estimates were all well above those of 2005, and
their long-term averages. Northern pintail and
scaup estimates were similar to last year’s, and to
their long-term averages.
In a typical year in southern Saskatchewan, 40-
60% of the wetlands present in May dry up by
July. However, this July, wetland abundance was
similar to that seen in May, which was expected to
provide abundant habitat and cover for waterfowl
broods. Habitat conditions in the grasslands
strata (32 and 33) changed little from May. The
western and southern portions of the grasslands
remained dry, and potential for waterfowl
production and recruitment was still rated poor to
fair. Good nesting and wetland habitat existed
across the central parts of the grasslands,
including the Missouri Coteau. Sheetwater was
still present across the northern and northwestern
grasslands and most wetlands had flooded
emergent vegetation. The northern grasslands
continued to have excellent upland and wetland
habitat conditions for waterfowl nesting and brood
rearing. Likewise, the northwest Parklands
(stratum 30) changed little since May. Good to
excellent waterfowl production and recruitment
was expected from this stratum. Conditions in the
northeast Parklands (stratum 31) also remained
unchanged, with very good upland habitat for
waterfowl nesting. The western two-thirds of the
stratum had excellent wetland habitat for brood
rearing. However, the eastern third of the stratum
was drier and wetland conditions were only fair to
good. Southeastern Saskatchewan, although
drier (poor to fair) south in Stratum 35, was wetter
(good to excellent) to the north in Stratum 34.
Overall, the survey area was rated good-excellent
for re-nesting potential and duckling production.
24
Southern Manitoba: After one of the warmest
winters on record, southern Manitoba (strata 24,
36-40) received substantial amounts of
precipitation during March and April. Runoff was
substantial and thousands of acres of cropland
were flooded in the Red and Assiniboine River
Valleys of the central and eastern portions of the
area. Strata 38, 39, and 40 of the southwestern
portions of Manitoba saw substantially improved
nesting cover and similar wetland numbers
relative to the good wetland conditions of 2005.
Higher water tables prevented farm activities in
wetland basins, so excellent residual nesting
cover remained around potholes. Excellent
conditions prevailed where these wetlands were
associated with natural grasslands. By contrast,
the far southwestern corner of Manitoba had much
less precipitation compared to areas just to the
northeast. Winter snow and spring rains were
virtually nonexistent and pothole numbers
appeared lower than in 2005. Dry conditions have
prevailed there for the last 2-3 years, which
rendered habitat poor for nesting waterfowl. In the
west-central portion of the Province (Strata 25, 36
and 37) conditions were notably drier, but still
appeared better than in the previous 3–4 years.
Strata 36 and 37 received substantially less
rainfall and are drier than areas further south, but
nesting cover still was better than average. The
Saskatchewan River area (Stratum 25) had higher
than average water levels which likely favored
diving ducks over dabbling ducks. Biologists
observed more divers but fewer dabblers than
usual in the area, as the high water produced
good nesting habitat for overwater-nesting diving
ducks, but probably prevented high densities of
dabblers from successfully breeding.
The May pond count was similar to the 2005
estimate and to the long-term average. Green-winged
teal, blue-winged teal, redheads,
canvasbacks, and lesser scaup were similar to their
2005 estimates and long-term averages. Total
ducks, mallards, and Northern shovelers were similar
to their 2005 estimates, but 16%, 35%, and 66%
above their long-term averages, respectively.
Northern pintail estimates were similar to those of
2005, but remained 49% below the long-term
average. The gadwall estimate was unchanged
relative to last year, and was 88% above the long-term
average. The American wigeon estimate was
53% lower than last year’s, and remained 74%
below the long-term average for the survey area.
Good May habitat conditions persisted into July
due to average precipitation that helped wetlands
retain their value for waterfowl. In southeastern
Manitoba (Stratum 38) sporadic rain during June
kept up with evaporation loss. Although these
wetlands are not exceptional habitat relative to the
rest of the survey area, (even when wet), they
remained in fair to good condition as of July. In
southwestern (Stratum 39) and the central
(Stratum 40) Manitoba brood habitat was good to
excellent, as many wetlands persisted due to their
excellent condition during May. The north central
areas (Stratum 36 and 37) were only in fair
condition for duckling production. Residual
vegetation from 2005 appeared to pay off in good
nest success, and survival of dabbler ducklings
should be good, due to the availability of good
brood rearing habitat. For the second year in a
row, permanent wetlands in Stratum 39 and 40
had good water depths and excellent emergent
vegetation, which likely benefited diving duck
production. Overall, good duck brood production
was predicted in southern Manitoba.
Montana and Western Dakotas: Eastern Montana
north of the Missouri River (Stratum 41)
experienced a relatively mild winter with above-normal
summer and fall precipitation. In addition
to rain and snow in March and April, this further
mitigated the effects of several years of drought.
However, even in wet years, the path and speed
of spring storm tracks typically produces a
complex mosaic of variable habitat quality in the
Eastern Montana-Western Dakotas survey area.
In contrast to the past several years, in northeast
Montana near Plentywood wetland conditions
were poor and spring vegetation growth was
sparse. A large central portion of stratum 41
bounded by Lewistown, Malta, and the North
Dakota border had above-average habitat
conditions, though in the far northwest portion of
the stratum, conditions were fair to poor. In
eastern Montana south of the Missouri River
(Stratum 42), conditions were average throughout
most of the region, with above average conditions
in the southeast. In particular, the area between
Lewistown and Glendive had good habitat, as did
the region east from Billings to the Dakota border,
which is usually dry. In the western Dakotas
(strata 43 and 44) conditions were average to
below average.
Overall in Montana and the Western Dakotas,
May pond counts were similar to the 2005
estimate, and 16% higher than the long-term
average. Total ducks were 48% higher than their
2005 estimate, and 18% above their long-term
average. Mallard numbers were also up, 76%
higher than last year’s estimate, and 36% above
the long-term average. American wigeon (+79%)
25
Northern pintails (+252%), and redheads (+315%)
were well above their 2005 estimates, but similar
to their long-term averages for the survey area.
Green-winged teal numbers were 59% lower than
last year’s estimate, but similar to their long-term
average. The blue-winged teal estimate was similar
to last year’s, and remained 32% above the long-term
average. The scaup estimate was similar to
last year’s, and remained 65% below the long
term average. Gadwall, Northern shoveler, and
canvasback estimates were similar to those of
2005, and to long-term averages.
In July, Eastern Montana and the western
Dakotas generally continued to reflect improved
waterfowl habitat quality relative to the previous
several years. Brood numbers reflected a
generally successful nesting season in most areas
and for the most part, class II broods were
observed. Some class I broods were also
observed, which suggested that late nesting and
renesting had also occurred. Conditions in the
northern portion of eastern Montana (Stratum 41)
were generally similar to those recorded in May.
The region east of Cut Bank, west of Havre and
north of Great Falls remained poor with many dry
basins and dry or fragmented stream channels.
Stratum 42 habitat quality was quite variable. The
southeastern region near Broadus and west to
Billings continued to have surprisingly favorable
water and brood habitat conditions, while the
central portion of the stratum was drier than in
May. Stratum 43 (western North Dakota)
conditions were largely unchanged since May,
with only fair habitat observed from the
Montana/North Dakota border to within 30 miles of
the Missouri River. In western South Dakota
(Stratum 44), the general trend in July was a
gradation of production habitat from fair in the
west to poor in the east.
Eastern Dakotas: Last winter was generally mild,
with less than average precipitation in eastern
North and South Dakota (Strata 45-49). The
wettest areas spanned the northern tier of
counties in ND from the Turtle Mountains east to
the Minnesota border, as well as a swath south
through statum 47 to the southeastern corner of
South Dakota. Conditions were especially
favorable in the northeastern corner of South
Dakota, which received good winter precipitation
and was the only portion of the crew area rated
excellent. However, much of the drift prairie in
South Dakota and the Coteau Slope in North
Dakota remained poor. Overall, wetland
conditions were improved compared to last year's
dry conditions. Although duck numbers in the
crew area were good, and vegetation
development was 2-3 weeks earlier than normal,
in the aggregate, the habitat in this crew area was
fair as of May 2006.
May ponds were 29% higher than the 2005
estimate, and similar to the long-term average.
The total duck estimate was 12% higher than the
2005 count and 23% above the long-term
average. 2006 estimates for all of the major duck
species in this crew area were similar to last
year’s estimates. Mallard numbers were 92%
above their long-term average. Gadwall (+37%)
and scaup (+42%) remained above their long-term
averages for the area. Pintail numbers were 44%
below their long-term average. American wigeon,
green-winged teal, blue-winged teal, Northern
shoveler, redhead, and canvasback estimates
were all similar to their long-term averages.
Wetland conditions in the survey area
deteriorated between May and July of 2006.
During June and the first half of July,
temperatures were average to above average in
the eastern Dakotas. There was little
precipitation, which added further to the
deterioration of habitat conditions observed in
May. During July reconnaissance flights, over half
of the crew area was considered in poor condition.
Slightly less than half of the unit was considered
fair or marginally fair and remaining small portions
of good habitat occurred in: the Turtle Mountains,
the Devils Lake region, the extreme southeastern
portion of stratum 46 in North Dakota, and in the
northern reaches of the Prairie Coteau in South
Dakota. Because of the general lack of water and
the overall depressed wetland conditions, little if
any second or late nesting was expected and
below average waterfowl production was expected
in the survey unit this year.
Northern Saskatchewan, Northern Manitoba, and
Western Ontario: In northern Saskatchewan and
northern Manitoba (strata 21-25), a very early
spring break-up occurred. Winter snowfall was
plentiful enough across both provinces to
recharge most beaver ponds and small lakes.
The early spring and good water conditions across
the landscape should bode well for waterfowl
production. Larger lakes and rivers tended to be
higher than recent years. In Manitoba, the lakes
associated with the Nelson River drainage were
especially high and muddy. Floodwater extended
well into the vegetation along the entire drainage.
Along other major rivers, the flooding was
prevalent, but not as severe. Although flooding
26
could disrupt nesting on large water bodies, the
early spring, coupled with ideal conditions on
smaller wetlands, should produce good waterfowl
production. Overall, the region was rated as
good. In Western Ontario (stratum 50), spring
was earlier than normal, lakes appeared full, and
river flow was normal to high. Marsh habitat in
Stratum 50 was also well flooded with adequate
water levels. Waterfowl production throughout the
survey area was expected to be good to excellent.
The total-duck estimate was 16% below the
2005 estimate, and 24% below the long-term
average. All the major species estimates in this
crew area were below long-term averages, except
for green-winged teal, where numbers were
unchanged from last year, and remained 54%
above the long-term average. The scaup estimate
was similar to last year’s, and remained 43%
lower than the long-term average. Mallards,
gadwall, blue-winged teal and Northern pintail
estimates were all similar to their 2005 estimates,
but were 43%, 41%, 69%, and 86% below their
long-term averages, respectively. American
wigeon numbers were 40% below last year’s
estimate, and 58% below their long-term average
for the region. Northern shovelers were 59%
below last year’s estimate, and 72% below their
long-term average. Redhead (-61%) and
canvasback (-67%) estimates declined relative to
last year’s, and were 82% and 77% below their
long-term averages for the survey area.
As of July, conditions were rated mostly good,
with some areas of fair, throughout most of
northern Saskatchewan and Northern Manitoba.
Northern Alberta, Northeastern British Columbia, and
Northwest Territories: Spring arrived two to three
weeks earlier than normal 2006 to this survey
area (strata 13-18, 20, 75-77), especially in
northern Alberta and the southern Northwest
Territories, and overall, breeding habitat was rated
as good. The southern portion of Northern Alberta
and Northeastern British Columbia (Stratum 77)
bounded by Fort McMurray, Slave lake and the
Peace River was dry because of below normal
winter and spring precipitation. Conditions there
were similar to, but not quite as dry as those of
2005. This area was rated fair. However, the
northern portion of the stratum received more
winter precipitation, and wetland conditions there
were rated good. At survey time, all water bodies
in Stratum 77 were ice free, which is highly
unusual. Flooding on the Athabasca Delta
(Stratum 20) was below normal, which decreased
available waterfowl breeding habitat. Most lake
levels were low; only Lake Claire was near
normal. Most water in the small wetlands and
deeper sloughs was not expected to last into the
summer, which likely adversely affected habitat for
waterfowl broods. Although spring was 2-3 weeks
early on the Delta, with no ice on Lake Claire,
Stratum 20 was rated as fair due to low water
levels. The southern Northwest Territories
(Stratum 17) also experienced an early spring.
Northern portions of the stratum were rated good,
but flooding due to heavy May rains in the
southern portion of the stratum meant conditions
there were only fair. The Canadian Shield (Strata
16 and 18) was rated good, as water levels were
near or above normal. Spring also began early in
this region, but phenology was delayed in early
and mid-May due to lower temperatures and
snow. Conditions in the Middle Mackenzie Valley
(Stratum 15) were good for waterfowl overall, due
to above average snowmelt, despite a dry swath
through the middle of this stratum. Spring
phenology was slightly delayed in Stratum 14
(Upper Mackenzie Valley Boreal Plains/Tundra),
but water levels were higher than normal, and
overall conditions were good. Considerable
flooding occurred on the Mackenzie River Delta
(Stratum 13) but weather-related survey delays
precluded more detailed reports on breeding
conditions in this area.
Total-duck numbers were similar to the 2005
estimate, and 28% below the long-term average
for the survey area. Green-winged teal numbers
were 72% higher than their 2005 estimate and
similar to their long-term average. Estimates of all
other species were similar to those of 2005.
Mallard (-49%), American wigeon (-38%),
Northern pintail (-67%), and scaup (-55%)
estimates were below their long-term averages for
the survey area. By contrast, the gadwall
estimate was 187% above the long-term average.
All other species estimates for the area were
similar to their long-term averages.
As of July, habitat conditions and the production
outlook for this survey area remained unchanged
since the survey was flown.
Alaska, Yukon Territory, and Old Crow Flats: In
Alaska, the Yukon Territory, and Old Crow Flats
(strata 1-12), breeding conditions depend largely
on the timing of spring phenology, because
wetland conditions are less variable than on the
prairies. In general, Alaska experienced a later
arrival of spring conditions than the early springs
of recent years. Overall, a normal phenology
occurred throughout Alaska and the Yukon
27
Territory. Ice lingered on the outer coast of the
Yukon Delta, the northern Seward Penninsula,
and on the Old Crow Flats. Some flooding
occurred on the Koyukuk, the lower Innoko, and
the lower Yukon Rivers. Overall, good waterfowl
production is anticipated this year in the
northwestern continental area, but cold weather in
early June could reduce the outlook somewhat.
Estimates of all duck species were similar to
those of 2005, with the exception of mallards,
which were 27% below their 2005 count, but 44%
above their long-term average, and Northern
shovelers, which were 39% below their 2005
count, and 53% above their long-term average.
Total duck (+34%), American wigeon (+61%), and
green-winged teal (+118%) estimates were all
above their long-term averages. This crew area
was the only one in which the American wigeon
estimate was above its long-term average. Blue-winged
teal were 100% lower than their long-term
average, but this survey area is not an important
breeding area for this species. Gadwall, Northern
pintail, redhead, canvasback, and scaup
populations all remained similar to their long-term
averages.
During June, weather in Alaska was variable.
Coastal Alaska was colder and wetter than normal
north of the Yukon River Delta, with normal
temperatures and precipitation south of it. Interior
Alaska experienced hard frosts, cold weather, and
heavy precipitation that could lower brood survival
Overall however, the forecast for production was
unchanged, with good waterfowl production
expected.
Eastern Survey Area: Spring-like conditions
arrived early in most of the eastern U.S. and
Canada (strata 51-72), with an early ice break-up
and relatively mild temperatures. Biologists
reported that habitat conditions were generally
good across most of the survey area. Most
regions had a warm, dry winter and a dry start to
spring. Extreme southern Ontario was relatively
dry during the survey period and habitats were in
fair to poor condition. However, precipitation after
survey completion improved habitat conditions in
this region. Abundant rain in May improved water
levels in Maine, the Maritimes, southern Ontario,
and Quebec, but caused some flooding in
southern Ontario and Quebec and along the coast
of Maine, New Brunswick, and Nova Scotia. In
Quebec, a very early spring assured good habitat
availability. Despite the early spring and the
abundance of spring precipitation, a dry winter still
left most of the marshes and rivers drier than in
past years. Many bogs were noticeably drier than
past years or dry entirely in a few cases. Winter
precipitation increased to the west and north,
resulting in generally good levels in central and
northern Ontario. Conditions were good to
excellent in central and northern Ontario due to
the early spring phenology, generally good water
levels, and warm spring temperatures.
Waterfowl habitat conditions in May, 2006 for
the Atlantic crew area ranged from fair in the
south to good in the north. Maine (stratum 62)
and the Maritime provinces of Canada
experienced a milder than normal winter with
spring break-up occurring by late April.
Phenology was at least two weeks advanced in all
strata. Early in May, New Brunswick (stratum 63),
Nova Scotia (stratum 64) and Prince Edward
Island (stratum 65) were extremely dry as a result
of limited snow pack run-off and little early spring
rainfall. Temperatures were also above normal.
Ponds and wetlands, however, were fully charged
and adequate cover was available for early
nesters. Southern portions of the survey area
experienced heavy rainfall and flooding early in
May and wet conditions continued throughout the
month. This flooding could have affected some
early nesters in parts of Maine, New Brunswick
and Nova Scotia. Newfoundland (stratum 66) and
Labrador (stratum 67) also had a milder than
normal winter with little snow until late. Runoff
was heavy in April, but by mid May streams and
ponds were drier than normal. During the last
week of May Newfoundland and Labrador
received abundant rainfall and an end to the dry
conditions. Phenology was at least two weeks
early in Newfoundland and Labrador, but good
nesting habitat was abundant and available for
waterfowl.
Winter precipitation and temperatures were
near long-term averages across much of southern
Ontario and Quebec (Strata 52-59). Spring
weather was mild, and precipitation was below
normal this spring in southern Ontario prior to the
survey. Extreme southern Ontario was relatively
dry during the survey period and habitats were
poor to fair. Wetland conditions improved near
the Bruce Peninsula and south of the Georgian
Bay with many seasonal wetlands in good
condition. In the hardwood-boreal transition
region east of Georgian Bay and into the
agricultural regions of the Ottawa River Valley
around Ottawa wetland conditions were also
generally good. Generally favorable habitat
conditions were observed throughout the St.
Lawrence Lowlands of New York. Wetland
habitats were in good condition in the St.
Lawrence Lowlands in Ontario north through
28
Quebec City due to good winter and spring
precipitation. Moderate flooding was observed
during the survey east of Ottawa and in
southeastern Quebec. Spring snow and ice-melt
were uncharacteristically early in northern Ontario
in the James Bay and Hudson Bay lowlands
(Strata 57-59) for the second straight year. Heavy
winter snowfall and a mild, early spring resulted in
excellent prospects for waterfowl production.
Waterfowl production throughout Central Ontario
(Stratum 52) was expected to be good to
excellent, due to an early spring phenology,
generally good water levels, warm spring
temperatures, and the resulting adequate brood
cover. Habitat conditions in southern Quebec
were drier than in recent years, but spring was
early. A large hydroelectric project along the
Eastmain River resulted in the loss of thousands
of hectares of boreal forest and associated
wetlands, and long-term effects are unclear.
Habitat within the lower North Shore and Anticosti
Island was considered good. Although marshes
and rivers were drier than in recent years,
waterfowl habitat was abundant. In boreal areas,
an early spring is more important than good water
levels so Quebec was rated good for waterfowl
production overall in 2006.
Mergansers, mallards, American black ducks,
ring-necked ducks, goldeneyes, scoters, scaup
and green-winged teal were all similar to their
2005 estimates (Table 13). American wigeon
(-51%) and buffleheads (-58%) were lower than
their 2005 estimates. None of the species
estimates in the eastern survey area differed from
long-term averages. As of July, habitat conditions
in the eastern survey area appeared unchanged
since surveys were flown.
Other areas: Wetland conditions in many areas
along the West Coast of the U.S. and Canada
improved relative to the dry conditions that prevailed
in 2005. In Oregon, total mallards in the breeding
population were estimated at 88,000, similar to
last year’s count of 83,000, but 20% below the
long-term average. The estimate for total ducks
(263,000) was up 17% relative to 2005, but was
11% below the long-term average.
In British Columbia, snow packs were variable
during the winter of 2005-06, good across
southern regions, but below average in the central
interior. Water levels in low elevation wetlands
were higher than in 2005, but overall, remained
poor. The total number of ducks observed in 2005
was similar to that of 2005, and to the (1988-2005)
long-term average (LTA). Total diving ducks were
36% higher than in 2005 and 24% above the LTA.
Total dabbling duck counts were 51% higher than
in 2005 and 8% above the LTA, but tests for
statistical significance are not available for these
counts. Mallard counts were down, but similar to
those of 2005 and to the long-term average.
These counts reflected both a dry spring and an
overall improvement in wetland conditions relative
to 2005 in central British Columbia. In California,
winter precipitation was average, but spring
weather brought precipitation totals to above
average over most of the state. Excellent
conditions prevailed in the northeastern part of the
state where above normal production was
expected. Elsewhere, duck nesting effort was late
but strong and production was expected to be
higher than normal. The total-duck estimate in
2006 was 649,400, which was similar to last year's
estimate of 615,000, and the long-term average.
The Mallard estimate in 2006 was 399,400, which
was not significantly different from the 2005
estimate or the long-term average.
In Nebraska, habitat conditions in the Sandhills
were initially good. Observers noted that duck
numbers were similar to those in recent years.
However, conditions deteriorated quickly as spring
progressed and most temporary wetlands were
dry by early June, and thus waterfowl production
was expected to be only fair.
Waterfowl numbers were down in the Great Lakes
states. In Minnesota, wetland conditions in spring
2006 were similar to those of 2005. Ice breakup
on most lakes across the state occurred
approximately 10 days earlier than average. April
and May temperatures were above normal.
Precipitation was above normal in April and below
normal in May. Minnesota pond numbers
decreased 12% relative to 2005, and were 15%
below the 1968-2005 average. Mallard numbers
continued to decline; the estimate of 161,000 was
down 33% relative to the 2005 estimate of 238,500
and was 28% below the long-term average, but a test
for statistical significance was unavailable for the
latter. Total duck numbers, at 529,000, were also
below their 2005 count. Spring precipitation was
above average over much of Wisconsin, and
wetland conditions were generally fair to good
when breeding ducks arrived. Wetland numbers
and conditions across the state were generally
improved relative to 2005, but still below long term
averages in many areas, which suggested
average conditions overall. Heavy rains during
the survey period and shortly thereafter likely
improved brood habitat in many areas. The total
duck estimate was 522,600 + 51,500, and the
mallard estimate was 219,500 + 30,500.
Wisconsin total duck numbers were 28% below the
29
2005 estimate and 22% above the 1974-2005
average. Mallard numbers were 31% below their
2005 level, and similar to the long-term mean. In
Michigan, the mallard estimate of 208,000 was
similar to that of 2005, and 50% below the 1992-2005
average
In the Atlantic Flyway states along the East Coast
of the U.S., conditions early in the breeding season
were generally favorable for nesting waterfowl,
with warm temperatures and dry to normal
moisture conditions. Heavy rains and cooler
temperatures during May and June in the northern
and western portions of the survey area may have
affected production through nest flooding and
brood losses. In the southern part of the survey
area, cool temperatures and poor wetland
conditions caused by less than normal
precipitation provided poor conditions for brood
rearing. Overall, field biologists’ reports suggest
that production this year may be reduced because
of poor habitat and weather conditions. Total duck
and mallard numbers from the Atlantic Flyway’s
Breeding Waterfowl survey were similar to 2005
estimates, and to their 1993-2005 averages.
Mallard Fall-flight Index
The mid-continent mallard population is composed
of mallards from the traditional survey area,
Michigan, Minnesota, and Wisconsin, and is 7.9 ± 0.2
million. This is similar to the 2005 estimate of 7.5 ±
0.3 million. The projected mallard fall flight index
was 9.8 ± 0.1 million, similar to the 2005 estimate of
9.3 ± 0.1 million birds (Fig. 3). These indices were
based on revised mid-continent mallard population
models, and therefore, differ from those previously
published (USFWS Adaptive Harvest Management
Report 2005, Runge et al. 2002).
0
2
4
6
8
10
12
14
16
18
1970 1975 1980 1985 1990 1995 2000 2005
Year
Millions
1
Fig. 5. Estimates and 90% confidence intervals for the size
of the mallard population in the fall.
REFERENCES
Drought Watch on the Prairies, 2006. Agriculture
and Agri-Food Canada.
http://www.agr.gc.ca/pfra/main_e.html
Link, W. A., and J. R. Sauer. 2002. A hierarchical
model of population change with application to
Cerulean Warblers. Ecology 83:2832-2840.
NOAA/USDA Joint Agriculture Weather Facility.
2006. Weekly Weather and Crop Bulletin.
Washington, DC.
http://www.usda.gov/oce/weather/pubs/Weekly/
Wwcb/index.htm
Runge, M. C., F. A. Johnson, J. A. Dubovsky, W.
L. Kendall, J. Lawrence, J. Gammonley.
2002. A revised protocol for the Adaptive
Harvest Management of Mid-Continent
Mallards. (migratorybirds.fws.gov/reports/
ahm02/MCMrevise2002.pdf)
Sauer, J.R., and S. Droege. 1990. Wood duck
population trends from the North American
Breeding Bird Survey. Pages 159-165 in L.H.
Frederickson, G. V. Burger, S.P. Havera, D.A.
Graber, R.E. Kirby, and T.S. Taylor, eds.
Proceedings of the 1988 North American Wood
Duck Symposium, St. Louis, MO.
U.S. Fish and Wildlife Service. 2006. Adaptive
Harvest Management: 2006 Duck Hunting
Season. U.S. Dept. Interior, Washington, D.C.
U.S. Fish and Wildlife Service. 2006.
Waterfowl Breeding Population Surveys, 2006,
Field Crew Reports.
http://migratorybirds.fws.gov/reports/reports.html
Wilkins, K. A., M. C. Otto, and M. D. Koneff 2006.
Trends in duck breeding populations, 1955-
2006. U.S. Dept. Interior, Washington, D.C.
26pp.
http://migratorybirds.fws.gov/reports/reports.ht
ml
30
STATUS OF GEESE AND SWANS
Abstract: We provide information on the population status and productivity of North American Canada geese
(Branta canadensis), brant (B. bernicla), snow geese (Chen caerulescens), Ross’ geese (C. rossii), emperor
geese (C. canagica), white-fronted geese (Anser albifrons), and tundra swans (Cygnus columbianus). In 2006,
the timing of spring snowmelt in important goose and swan nesting areas in most of the Arctic and subarctic
was earlier than average. Delayed nesting phenology or reduced nesting effort was indicated for only Alaska’s
Yukon Delta, other coastal areas of Alaska, and near the Mackenzie River Delta in the western Canadian Arctic.
Primary abundance indices in 2006 increased from 2005 levels for 13 goose populations and decreased for 11
goose populations. Primary abundance indices in 2006 for both populations of tundra swans increased from
2005 levels. The Mississippi Flyway Giant and the Atlantic Canada goose populations, the Western
Arctic/Wrangel Island snow goose population, and Pacific white-fronted goose population displayed significant
positive trends during the most recent 10-year period (P < 0.05). The Short Grass Prairie Canada goose and
the Mid-continent light goose populations showed significant negative 10-year trends. The forecast for the
production of geese and swans in North America in 2006 is generally favorable and improved from that of 2005.
This section summarizes information regarding the
status, annual production of young, and expected fall
flights of goose and tundra swan populations in North
America. Information was compiled from a broad
geographic area and is provided to assist managers
in regulating harvest.
Most populations of geese and swans in North
America nest in the Arctic or subarctic regions of
Alaska and northern Canada (Fig. 1), but several
Canada goose populations nest in temperate regions
of the United States and southern Canada
(“temperate-nesting” populations). The annual
production of young by northern-nesting geese is
influenced greatly by weather conditions on the
breeding grounds, especially the timing of spring
snowmelt and its impact on the initiation of nesting
activity (i.e., phenology). Persistent snow cover
reduces nest site availability, delays nesting activity,
and often results in depressed reproductive effort and
productivity. In general, goose productivity will be
better than average if nesting begins by late May in
western and central portions of the Arctic, and by
early June in the eastern Arctic. Production usually is
poor if nest initiations are delayed much beyond 15
June. For temperate-nesting Canada goose
populations, recruitment rates are less variable, but
productivity is influenced by localized drought and
flood events.
METHODS
We have used the most widely accepted
nomenclature for various waterfowl populations, but
they may differ from other published information.
Species nomenclature follows the List of Migratory
Birds in Title 50 of the Code of Federal
Regulations, Section 10.13. Some of the goose
populations described herein are comprised of more
than 1 subspecies and some light goose populations
contain 2 species (i.e., snow and Ross’ geese).
Population estimates for geese are derived from a
variety of surveys conducted by biologists from
federal, state, and provincial agencies, and
universities (Appendices B, I, and J). Surveys
include the Midwinter Survey (MWS, conducted each
January in wintering areas), the Waterfowl Breeding
Population and Habitat Survey (WBPHS, see Duck
section of this report), surveys that are specifically
designed for various populations, and others. When
survey methodology allowed, 95% confidence
intervals were presented with population estimates.
The 10-year trends of population estimates were
calculated through regression of the natural logarithm
of survey results on year, and slope coefficients were
presented and tested for equality to zero (t-test).
Changes in population indices between the current
and previous years were calculated and, where
possible, assessed with a z-test using the sum of
sampling variances for the 2 estimates. Primary
abundance indices, those related to management
plan population objectives, are described first in
population-specific sections and graphed when data
are available.
Because this report was completed prior to the final
annual assessment of goose and swan reproduction,
the annual productivity of most populations is only
predicted qualitatively. Information on habitat
conditions and forecasts of productivity were based
primarily on observations made during various
waterfowl surveys and on interviews with field
biologists. These reports provide reliable information
for specific locations, but may not provide accurate
assessment for the vast geographic range of
waterfowl populations.
31
Fig. 1. Important goose nesting areas in Arctic and subarctic North America.
La Perouse Bay
Cape Henrietta
Maria
Banks
Island
Bylot
Island
Southampton
Island
Ungava
Peninsula
James
Bay
Akimiski
Island
McConnell
River
Queen
Maud
Gulf
Copper
River
Yukon River
Kuskokwim River
Yukon-Kuskokwim
Delta
Baffin Island
Foxe
Basin
Labrador
Plain of
Koukdjuak
Wrangel
Island
Anderson
River
Mackenzie
River Delta
Victoria I
C. Churchill
North Slope
Hudson Bay
Parry
Islands
Greenland
King
William
I
32
RESULTS AND DISCUSSION
Conditions in the Arctic and Subarctic
The timing of spring snowmelt in nearly all
important northern goose and swan nesting areas in
2006 was earlier than average. Many areas reported
lower than average winter snow accumulation and
higher than average temperatures during April-June
2006. Delayed nesting phenology or reduced
nesting effort was indicated for only Alaska’s Yukon
Delta, other portions of western Alaska, and near the
Mackenzie River Delta in the western Canadian
Arctic. The snow and ice cover graphic (Fig. 2,
National Oceanic and Atmospheric Administration)
illustrates many similarities in the progression of
snowmelt by 2 June in 2006 and 2005. Nesting
phenology during 2005 was also widely reported as
earlier than average.
Fig. 2. The extent of snow and ice cover in North America on 2
June 2006 and 2 June 2005 (data from National Oceanic and
Atmospheric Administration).
Conditions in Southern Canada and the United
States
Conditions that influence the productivity of
Canada geese vary less from year to year in these
temperate regions than in the Arctic and subarctic.
Given adequate wetland numbers and the
absence of flood events, temperate-nesting
Canada geese are reliably productive. Wetland
abundance increased in many prairie and
deciduous forest areas in 2006 and may benefit
nesting geese. However, widespread spring
flooding reduced goose production in some areas
(e.g., New England, Utah). Drought impacted
fewer areas in 2006 than in 2005, but still
depressed production in some locales (e.g.,
western Oklahoma). Most temperate-nesting
Canada goose populations likely experienced
average or above average nesting conditions in
2006.
Status of Canada Geese
North Atlantic Population (NAP): NAP Canada
geese principally nest in Newfoundland and
Labrador. They generally commingle during winter
with other Atlantic Flyway Canada geese, although
NAP geese have a more coastal distribution than
other populations (Fig. 3).
During the 2006 WBPHS, biologists estimated
49,200 (+ 24,800) indicated pairs (singles plus
pairs) within NAP range (strata 66 and 67), 4%
fewer than in 2005 (P = 0.903, Fig. 4). Indicated
pair estimates have declined an average of 3%
per year during 1997-2006 (P = 0.228). The 2006
estimate of 118,000 (+ 57,600) total NAP Canada
geese was 9% lower than last year’s estimate (P =
0.784). Preliminary information from the 2006
expanded CWS helicopter plot surveys indicated
that numbers of geese increased from 2005 levels
and that clutch sizes were again high. Spring
phenology was nearly 2 weeks early and nesting
conditions were favorable for geese in
Newfoundland and Labrador in 2006. A fall flight
similar to that of 2005 is expected.
Year
'96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
0
20
40
60
80
100
120
140
160
Fig. 4. Estimated number (and 95% confidence intervals) of North
Atlantic Population Canada geese breeding pairs during spring.
33
Tall Grass
Prairie
North
Atlantic
Southern
James Bay
Lesser and
Atlantic Taverner’s
Mississippi
Valley
Short Grass
Prairie
Pacific
Dusky
Cackling
Hi-line
Western Prairie
Eastern
Prairie
Atlantic
Flyway
Resident
Aleutian
Rocky
Mountain
Great
Plains
Mississippi
Flyway
Giant
Fig. 3. Approximate ranges of Canada goose populations in North America.
34
Atlantic Population (AP): AP Canada geese nest
throughout much of Quebec, especially along
Ungava Bay, the eastern shore of Hudson Bay, and
on the Ungava Peninsula. The AP winters from New
England to South Carolina, but the largest
concentrations occur on the Delmarva Peninsula
(Fig. 3).
Spring surveys in 2006 yielded an estimate of
160,000 (+ 32,200) indicated breeding pairs, 1%
fewer than in 2005 (P = 0.909, Fig. 5). Breeding pair
estimates have increased an average of 14% per
year during 1997-2006 (P < 0.001). The estimated
total spring population of 1,135,500 (+ 237,700)
geese in 2006 was nearly identical to that of last year
(P = 0.973). Spring temperatures in 2006 were mild
and breeding areas were largely free of snow by
early May, leading to a second consecutive year of
earlier than average nesting phenology in much of
the AP range. The proportion of indicated pairs
observed as singles (62%) surpassed the 2005
record-high level, suggesting another excellent
nesting effort this year. Clutch sizes and nest
densities on the Ungava Peninsula study areas in
2006 were slightly above average, and productivity
there was expected to be average or better. Range-wide
production was expected to be good and a fall
flight similar to that of last year is expected.
Year
'88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
0
25
50
75
100
125
150
175
200
Fig. 5. Estimated number (and 95% confidence intervals) of
Atlantic Population Canada goose breeding pairs in northern
Quebec.
Atlantic Flyway Resident Population (AFRP): This
population of large Canada geese inhabits southern
Quebec, the southern Maritime provinces, and all
states of the Atlantic Flyway (Fig. 3).
In 2003, the calculation method of the spring AFRP
index was changed (survey methodology did not
change). Beginning this year we discuss the new
indices of the AFRP, but include the old indices
graphically (Fig. 6). Surveys during spring 2006
estimated 1,149,100 (+ 208,900) Canada geese in
this population, 2% fewer than in 2005 (1,167,100, P
= 0.903). These indices have increased an average
of 2% per year over the last 4 years (P = 0.547).
Spring conditions in 2006 were near average in much
of AFRP range. However, widespread flooding in the
northeastern United States negatively impacted
nesting there. Observations during banding
programs in those areas indicated gosling production
may have been reduced about 25% from average
levels. The 2006 fall flight is expected to be
somewhat less than average.
Year
'89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
0
200
400
600
800
1000
1200
1400
1600
New index
Old index
Fig. 6. Estimated number (and 95% confidence intervals) of
Atlantic Flyway Resident Population Canada geese during spring.
Southern James Bay Population (SJBP): This
population nests on Akimiski Island and in the
Hudson Bay Lowlands to the west and south of
James Bay. The SJBP winters from southern
Ontario and Michigan to Mississippi, Alabama,
Georgia, and South Carolina (Fig. 3).
Breeding ground surveys indicated a spring
population of 160,400 (+ 35,700) Canada geese in
2006, 247% higher than last year’s potentially biased
survey (P < 0.001), and 59% higher than the 2004
survey estimate (P = 0.24, Fig. 7). The 2006 level
was a record high since surveys started in 1990.
Spring population estimates have decreased an
average of 2% per year since 1997 (P = 0.646). The
estimate of breeding pairs in 2006 increased to
64,400 (+ 13,900), 205% higher than in 2005 (P <
0.001), and 71% higher than in 2004 (P = 0.075).
Biologists believed the 2005 survey results
underestimated the population due to unusual
variation in survey timing and reduced goose
detection resulting from the use of a different survey
aircraft. Surveys in 2006 were conducted within the
target period with the traditionally used aircraft.
Survey biologists indicated that temperate-nesting
molt migrants likely were not a factor in survey
estimates during 2004-2006. Lower than average
winter snowfall and above average spring
35
temperatures contributed to a spring thaw in 2006
that was even earlier than in 2005, and 3-4 weeks
earlier than average. On Akimiski Island, nesting
phenology was similar to 2005, which was the
earliest recorded since 1993. Nest density and
average clutch size on Akimiski Island were above
the recent average. Nest success there was lower
than in 2005, but still higher than average. Biologists
anticipate the fall flight in 2006 to be well above
average.
Year
'90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
20
40
60
80
100
120
140
160
180
Fig. 7. Estimated total population (and 95% confidence intervals) of
Southern James Bay Population Canada geese during spring.
Mississippi Valley Population (MVP): The principal
nesting range of this population is in northern
Ontario, especially in the Hudson Bay Lowlands,
west of Hudson and James Bays. MVP Canada
geese primarily concentrate during fall and winter in
Wisconsin, Illinois, and Michigan (Fig. 3).
Year
'89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
100
200
300
400
500
600
Fig. 8. Estimated number (and 95% confidence intervals) of
Mississippi Valley Population breeding Canada geese during
spring.
Breeding ground surveys conducted in 2006
indicated the presence of 384,400 (+ 64,100) MVP
breeding adults, 11% more than in 2005 (P = 0.339),
and the highest number recorded since 1999.
Estimates of breeding adults have declined an
average of 1% per year during 1997-2006 (P =
0.495). Surveys indicated a total population of
705,000 (+ 138,000) Canada geese, a 31% increase
from 2005 (P = 0.061, Fig. 8). Molt migrant Canada
geese likely had little impact on the total goose
estimate this year. For the second consecutive year,
spring snowmelt occurred nearly a month earlier than
in 2004 and much earlier than average. Residents of
Peawanuck, Ontario reported the earliest break-up of
the Winisk River within memory. Favorable spring
conditions and higher than average nest densities
suggest the 2006 fall flight should be similar to that of
2005.
Eastern Prairie Population (EPP): These geese
nest in the Hudson Bay Lowlands of Manitoba and
concentrate primarily in Manitoba, Minnesota, and
Missouri during winter (Fig. 3).
Year
'72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
50
100
150
200
250
300
350
Fig. 9. Estimated number (and 95% confidence intervals) of
Eastern Prairie Population Canada geese during spring.
The 2006 spring estimate of EPP geese was
185,400 (+ 30,400), 27% lower than the 2005
estimate (P = 0.002, Fig. 9). Spring estimates have
increased an average of 3% per year over the last 10
years (P = 0.222). The 2006 survey estimate of
singles and pairs was 134,800 (+ 18,700), 17% lower
than last year (P = 0.063). Estimates of these
population components have increased an average
of 2% per year during 1997-2006 (P = 0.113). The
estimated number of productive geese in 2006 was
similar to 2005. Mild April temperatures and low
winter snowfall led to an early nesting chronology
throughout EPP range. This year, biologists on Cape
Churchill observed a median hatch date of 17 June,
about 1 week earlier than the long-term average
(1976-2005). Nest density in 2006 was the highest
recorded since 1990 and mean clutch size (4.1) was
above the long-term average. Estimates of nest
36
density, clutch size, and nest success indicated
production would be better than most recent years,
but still slightly below the average value since 1976.
Canada goose nest density, clutch size, and nest
success indices compiled at the Broad River also
indicated good production in 2006. A fall flight similar
to that of 2005 is expected.
Mississippi Flyway Giant Population (MFGP):
Giant Canada geese have been reestablished or
introduced in all Mississippi Flyway states. This
subspecies now represents a large proportion of all
Canada geese in the Mississippi Flyway (Fig. 3).
During spring 2006 biologists tallied 1,686,300
MFGP geese, a record high, and 7% more than were
tallied in 2005 (Fig. 10). These estimates have
increased an average of 5% per year since 1997 (P <
0.001). Most MFGP states expected average
production in 2006, with especially good nesting
conditions in Iowa, Indiana, and Michigan. A large
fall flight, similar to that of 2005 is expected.
Year
'93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05 '06
Thousands
600
800
1000
1200
1400
1600
1800
Fig. 10. Estimated number of Mississippi Flyway Giant Population
Canada geese during spring.
Western Prairie and Great Plains Populations
(WPP/GPP): The WPP is composed of mid-sized
and large Canada geese that nest in eastern
Saskatchewan and western Manitoba. The GPP is
composed of large Canada geese resulting from
restoration efforts in Saskatchewan, North Dakota,
South Dakota, Nebraska, Kansas, Oklahoma, and
Texas. Geese from these breeding populations
commingle during migration with other Canada
geese along the Missouri River in the Dakotas and
on reservoirs from southwestern Kansas to Texas
(Fig. 3). These 2 populations are managed jointly
and surveyed during winter.
During the 2006 MWS, 444,400 WPP/GPP geese
were counted, 7% more than in 2005 (Fig. 11).
These indices have shown no trend during 1997-
2006 (P = 0.986). In 2006, the estimated spring
population in the portion of WPP/GPP range included
in the WBPHS was 733,200 (+ 116,000) geese, 24%
more than last year (P = 0.056). The WBPHS
estimates have increased an average of 4% per year
since 1997 (P = 0.005). Goose production in the
WPP range likely increased from 2005 due to slightly
improved wetland conditions. Most states throughout
GPP range reported near average nesting conditions
and production. However, production in central North
Dakota and in central and western Oklahoma was
likely reduced by drought. A spring snow storm in
Nebraska may have negatively impacted some
geese there, but production was still expected to be
average or above average. A fall flight similar to that
of last year is expected.
Year
'82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
100
200
300
400
500
600
700
800
Fig. 11. Estimated number of Western Prairie Population/Great
Plains Population Canada geese during winter.
Tall Grass Prairie Population (TGPP): These small
Canada geese nest on Baffin (particularly on the
Great Plain of the Koukdjuak), Southampton, and
King William Islands; north of the Maguse and
McConnell Rivers on the Hudson Bay coast; and in
the eastern Queen Maud Gulf region. TGPP Canada
geese winter mainly in Oklahoma, Texas, and
northeastern Mexico (Fig. 3). These geese mix with
other Canada geese on wintering areas, making it
difficult to estimate the size of the winter population.
During the 2006 MWS in the Central Flyway,
499,800 TGPP geese were counted, 25% more than
in 2005 (Fig. 12). These estimates have increased
an average of 6% per year during 1997-2006 (P =
0.236). Average spring temperatures throughout
western and southern Nunavut reached record highs
in 2006. Biologists report that the timing of snowmelt
and nesting activities in 2006 were earlier than recent
years in the Queen Maud Gulf Sanctuary and on
Southampton and King William Islands, but near
average at the McConnell River. Satellite imagery
and climate data suggest that Baffin Island snowmelt
was earlier than in 2005. Limited information
37
suggests production of TGPP Canada geese will be
increased from that of 2005.
Year
'72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
100
200
300
400
500
600
700
*
* Changes in survey coverage or methodology - not comparable with previous surveys
*
Fig. 12. Estimated number of Tall Grass Prairie Population Canada
geese in the Central Flyway during winter.
Short Grass Prairie Population (SGPP): These
small Canada geese nest on Victoria and Jenny Lind
Islands and on the mainland from the Queen Maud
Gulf west and south to the Mackenzie River and
northern Alberta. These geese winter in
southeastern Colorado, northeastern New Mexico,
and the Oklahoma and Texas panhandles (Fig. 3).
Year
'70 '72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
100
200
300
400
500
600
700
800
Fig. 13. Estimated number of Short Grass Prairie Population
Canada geese during winter.
The MWS index of SGPP Canada geese in 2006
was 234,700, 33% higher than in 2005 (Fig. 13).
These indices have declined an average of 10% per
year since 1997 (P = 0.024). In 2006, the estimated
spring population of SGPP geese in the Northwest
Territories (WBPHS strata 13-18) was 87,500 (+
33,500), a 25% decrease from 2005 (P = 0.326).
WBPHS estimates have increased an average of 5%
per year since 1997 (P = 0.159). Spring break-up
was nearly a month earlier than average near
Kugluktuk (west of Queen Maud Gulf), and the
average spring temperatures throughout western
Nunavut reached record highs in 2006. Goose
nesting phenology near Queen Maud Gulf in 2006
was about a week earlier than average. Snowmelt
on Victoria Island also was earlier than average.
Surveys near the Mackenzie Delta suggested a
modest nesting effort by Canada geese there.
Wetland conditions in WBPHS strata 13-18 were
considered favorable for waterfowl nesting. Although
specific information is limited, production from SGPP
geese is expected to be higher than average in 2006.
Hi-line Population (HLP): These large Canada
geese nest in southeastern Alberta, southwestern
Saskatchewan, eastern Montana and Wyoming, and
in Colorado. They winter in these states and central
New Mexico (Fig. 3).
The 2006 MWS indicated a total of 247,300 HLP
Canada geese, 19% more than last year’s estimate
(Fig. 14). The MWS estimates have increased an
average of 4% per year since 1997 (P = 0.119). The
WBPHS yields an estimate of the HLP spring
population in Saskatchewan, Alberta, and Montana.
The 2006 WBPHS estimate was 208,000 (+ 43,600),
12% lower than the 2005 estimate (P = 0.401). The
WBPHS population estimates have shown no annual
trend during 1997-2006 (P = 0.723). The state
estimate of the HLP breeding population in Wyoming
was 19,000, an increase of 3% from 2005. Wetland
conditions were good to excellent in the northern
portion of HLP range, but average to poor in southern
areas. The fall flight of HLP geese is expected to be
similar to that of 2005.
Year
'70 '72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
50
100
150
200
250
300
Fig. 14. Estimated number of Hi-line Population Canada geese
during winter.
Rocky Mountain Population (RMP): These large
Canada geese nest in southern Alberta and western
Montana, and the inter-mountain regions of Utah,
Idaho, Nevada, Wyoming, and Colorado. They
winter mainly in central and southern California,
38
Arizona, Nevada, Utah, Idaho, and Montana (Fig. 3).
Spring population estimates from RMP states and
provinces in 2006 totaled 140,600, 19% lower than in
2005 (Fig. 15). These estimates have increased an
average of 3% per year during the last 10 years (P =
0.186). Population indices in 2006 increased in
Wyoming, Colorado, and Nevada, but decreased in
Alberta, Montana, and Utah. Wetland conditions in
Alberta and Montana improved since 2005 which
may increase goose production there. Utah
experienced widespread spring flooding and
biologists there expected gosling production to be
reduced. The fall flight of RMP geese is expected to
be similar to that of last year.
Year
'70 '72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
20
40
60
80
100
120
140
160
180
200
Fig. 15. Estimated number of Rocky Mountain Population Canada
geese during spring.
Pacific Population (PP): These large Canada
geese nest and winter west of the Rocky Mountains
from northern Alberta and British Columbia south
through the Pacific Northwest to California (Fig. 3).
Most PP geese are surveyed in Alberta and
Oregon. In 2006, survey indices in Alberta (WBPHS
strata 76-77) and Oregon were 73,200 (+ 43,400)
and 41,900, respectively. These indices represent an
increase of 65% (P = 0.255) and no change,
respectively, from indices in 2005. Breeding
population indices in 2006 also increased from the
2005 levels in British Columbia and Washington, but
decreased in California and Nevada. Habitat
conditions were favorable in northern Alberta.
California and Utah expected gosling production in
2006 to be below average due to spring storms or
flooding events. Wetland conditions in Nevada and
the production outlook there have improved since
2005. A fall flight similar to that of 2005 is expected.
Dusky Canada Geese: These mid-sized Canada
geese predominantly nest on the Copper River Delta
of southeastern Alaska, and winter principally in the
Willamette and Lower Columbia River Valleys of
Oregon and Washington (Fig. 3).
The size of the population is estimated through
observations of marked geese during December and
January. The 2005-2006 population estimate was
11,900 (+ 2,200), 45% lower than in 2004-2005 (P <
0.001, Fig. 16). These estimates have decreased an
average of 1% per year during the last 10-year period
(P = 0.763). Preliminary results from the 2006 spring
survey of Copper River Delta dusky geese indicated
the index of singles and pairs decreased 25%, and
total geese decreased 34% from last year’s high
levels. Although lower than in 2005, the 2006
breeding ground indices exceeded levels recorded in
all other years since 1998. In 2006, the Copper River
Delta experienced a cold spring, resulting in
snowmelt and nesting phenology being somewhat
later than average (by less than 1 week). Nest
success was lower than average in 2006 based on
predation rates observed at artificial nest islands. A
fall flight somewhat lower than that of last year is
expected.
Year
'70 '72 '74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
5
10
15
20
25
30
Fig. 16. Estimated number of dusky Canada geese during winter.
Cackling Canada Geese: Cackling Canada geese
nest on the Yukon-Kuskokwim Delta (YKD) of
western Alaska. They primarily winter in the
Willamette and Lower Columbia River Valleys of
Oregon and Washington (Fig. 3).
The primary index of this population was a fall
estimate from 1979-1998. Since 1999, the index has
been an estimate of the subsequent fall population
derived from spring counts of adults on the YKD.
The fall estimate for 2006 is 169,300, 8% higher than
that of 2005. These estimates have decreased an
average of 2% per year since 1997 (P = 0.246,
Fig. 17). Surveys in the coastal zone of the YKD
during spring 2006 indicated increases of 10% and
8% in the numbers of indicated pairs and total geese,
respectively, from 2005 estimates. Spring snowmelt
on the YKD was about 1 week later than average,
39
but goose nesting phenology was only 2-3 days later
than the long-term average. Yukon Delta nesting
surveys indicated that clutch sizes in 2006 were near
the 1997-2005 average. Fox predation appeared to
be low in 2006 and nest success rates should be
high. A fall flight similar to that of last year is
expected.
Year
'80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
20
40
60
80
100
120
140
160
180
200
220
Fig. 17. Number of cackling Canada geese estimated from fall and
spring surveys.
Lesser and Taverner’s Canada Geese: These
subspecies nest throughout much of interior and
south-central Alaska and winter in Washington,
Oregon, and California (Fig. 3). Taverner’s geese
are more associated with the North Slope and tundra
areas, while lesser Canada geese tend to nest in
Alaska’s interior. However, these subspecies mix
with other Canada geese throughout the year and
reliable estimates of separate populations are not
presently available.
The 2006 estimate of Canada geese within
WBPHS strata predominantly occupied by these
subspecies (strata 1-6, 8, 10-12) was 61,300, nearly
identical to the 2005 estimate (61,000). These
estimates have declined an average of 5% per year
since 1997 (P = 0.012). In Alaska’s interior, spring
break-up varied from near average to 1 week later
than average. Substantial flooding was limited to the
Koyukuk area. Production of lesser Canada geese in
the interior is expected to be good or very good.
Spring snowmelt on the North Slope was 5-7 days
earlier than average and goose production of
Taverner’s geese there is expected to be good.
Aleutian Canada Geese (ACG): The Aleutian
Canada goose was listed as endangered in 1967
(the population numbered approximately 800 birds in
1974) and was de-listed in 2001. These geese now
nest primarily on the Aleutian Islands, although
historically they nested from near Kodiak Island,
Alaska to the Kuril Islands in Asia. They now winter
along the Pacific Coast to central California (Fig. 3).
The population estimate for these geese has been
based on observations of neck-banded geese in
California. At the time this report was prepared the
2005-2006 population estimate was not available.
During 2004-2005, the population estimate was
63,800 (+ 12,400), 9% lower than the record high
estimate in 2003-2004 (P = 0.555, Fig. 18). Those
indirect estimates had increased an average of 12%
per year during winters of 1995 through 2005 (P <
0.001). In 2006, the Aleutian Islands experienced a
late spring snowmelt and nesting phenology of
Aleutian Canada geese was somewhat delayed.
However, clutch sizes were near average and reports
from Buldir Island indicate production was average or
better there. Production in 2006 may be near
average but likely will be reduced from the 2 previous
years.
Year
'74 '76 '78 '80 '82 '84 '86 '88 '90 '92 '94 '96 '98 '00 '02 '04 '06
Thousands
0
10
20
30
40
50
60
70
Fig. 18. Number of Aleutian Canada geese estimated from
winter estimates and mark-resight methods.
Status of Light Geese
The term light geese refers to both snow geese
and Ross’ geese (including both white and blue
color phases), and the lesser (C. c. caerulescens)
and greater (C. c. atlantica) snow goose
subspecies. Another collective term, mid-continent
light geese, includes lesser snow and
Ross’ geese of 2 populations: the Mid-continent
Population and the Western Central Flyway
Population.
Ross’ Geese: Most Ross’ geese nest in the Queen
Maud Gulf region, but increasing numbers nest along
the western coast of Hudson Bay, and Southampton,
Baffin, and Banks Islands. Ross’ geese are present
in the range of 3 different populations of light geese
and primarily winter in California, New Mexico,
40
Atlantic
Brant
Pacific
&
WHA Brant
Fig. 19. Approximate ranges of brant and snow, Ross', and white-fronted goose populations in North America.
Pacific Mid-continent
Populations of Greater
White-fronted Geese
Mid-continent
Western Central
Flyway
Populations of
Light Geese
Wrangel
Island
Populations of
Brant
Ross'
Geese
Greater
Snow
Geese
Western
Arctic
Populations of
Light Geese
41
Texas, and Mexico, with increasing numbers in
Louisiana and Arkansas (Fig. 19).
Year
'93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05
Thousands
100
200
300
400
500
Fig. 20. Estimated number adult Ross’ geese nesting at the Karrak
Lake colony, Nunavut.
Ross’ geese are annually surveyed at only 2 of
their numerous nesting colonies. More
comprehensive aerial photography inventories and
groundwork (to identify proportions of snow and
Ross’ geese within colonies) are conducted only
periodically. The largest Ross’ goose colonies are in
the Queen Maud Gulf Sanctuary. Biologists there