Waterfowl breeding population survey for Montana

              Waterfowl Breeding Population Survey
for
MONTANA
2001
Cut Bank Havre
Great Falls
Malta
Plentywood
Lewistown
Billings
Sidney
Glendive
Miles City
Broadus
42
41
Title: Waterfowl Breeding Population Survey for Montana
Strata Surveyed: 41 and 42
Dates: May 5 - 18, 2001
Data Supplied By: U.S. Fish and Wildlife Service (USFWS)
Division of Migratory Bird Management (DMBM)
Aerial Crew:
Pilot/Observer: James F. Voelzer, Chief
Waterfowl Population Surveys DMBM
Observer: Ray Bentley, Flyway Biologist Trainee DMBM
Ground Crew:
Leader: Allison Arnold, Wildlife Biologist, EPIC, L.L.C.
Dripping Springs, Texas
Assistant: Vincent Griego, Refuge Operations Specialist, USFWS
Sonny Bono Salton Sea NWR Complex
Calipatria, California
Abstract:
The 2001 Waterfowl Breeding Population Survey for Montana was completed on May 18 with
all segments and transects covered as outlined in the survey design. A general drought condition
existed across stratum 41 and 42 with poor habitat conditions in the west improving to good
habitat conditions in the east. Pond counts were below the previous year’s estimate by 5%
(rounded) and below 10-year and long term means by 50% and 42% respectively.
Waterfowl population estimates reflected the dry conditions with declines in all dabbler species
from the 10-year and long term means. Mallard showed a 21% decline from 2000, a 35% decline
from the 10 year mean, and 19% below the long term mean. Northern pintail showed a similar
historic trend, however, 2001 population estimates were up by 34% over the previous year.
Population estimates of divers were more variable with short term increases in redhead,
canvasback, and scaup. Canada goose indices changed little from the previous year and 10-year
mean remaining well above (65%) the long term mean. Though breeding and potential brood
conditions appear to be normal in the eastern portion of the strata extensive areas of drought are
expected to yield below average production overall.
Methods:
Procedures followed in conducting the survey are described in the Standard Operating
Procedures for Aerial Breeding Ground Surveys in North America, Section III, revised 1987.
The survey design for Montana included 12 air/ground comparison segments comprising 6.7% of
the total 280 segments flown. Two segments in the northwestern region of stratum 41 were
partially omitted due to adverse flying conditions with a corresponding adjustment in the area
expansion factor.
Air and ground crew members met in Pierre South Dakota on April 30. Survey flights in
Montana were initiated on May 5 and continued through May 18. Flights were canceled on May
6 due to adverse weather conditions and aircraft mechanical problems forced cancellation of
flights for 5 days (May 12-17). Data for the western Dakotas was sent to John Solberg for
inclusion in the overall South Dakota and North Dakota report.
A Cessna TR182 aircraft (N705) was used to fly the survey over approximately 52 hrs of flight
time. Survey personnel included Jim Voelzer as pilot/observer; Ray Bentley as right seat
observer; Allison Arnold as ground crew leader, and Vincent Griego as ground crew assistant.
This was Jim’s 24th season flying this particular survey area and Ray’s 3rd season as observer.
2001 was Allison’s 4th year as ground crew leader and Vincent’s 2nd season as assistant.
Aerial observations were collected using onboard PC computers interfaced with the aircraft GPS
receiver. Each observation was marked with time and location and processed using software
developed by Jack Hodges, USFWS/DMBM, Juneau, Alaska. Field processed data files were
then sent to Mark Otto, Population and Habitat Assessment Section (PHAS) USFWS/DMBM
and Kristi Wilkins (PHAS) in Laurel, MD for application of visibility correction factors and table
compilation.
Weather and H abitat Conditions:
Overall habitat conditions for eastern Montana were fair to poor in 2001. A general
improvement of pond numbers, flowing stream drainage, and shoreline vegetation occurred from
the front range east toward the North Dakota border. The northeastern and southeastern corners
of the state showed good habitat with an area of poor conditions positioned centrally in the
general area between Glendive and Glascow. The U.S. Palmer Drought Index (PDI) and
NOAA’s drought monitor agree with crew observations classifying central Montana as a
“severe” drought area progressing east to “abnormally dry” with the observed improved habitat
conditions in the northeast. Total pond estimates were 50% below the ten year mean and 42%
below the long term mean (Table 2.) with 2001 being the second driest year on record surpassed
only by 1980.
Stratum 41 (North of the Missouri River)
This stratum showed pond counts to be very close (N = 74,226) to the previous
year’s estimate with similar trends in areas of poor, fair, and good habitat
conditions. Water levels in most basins are below conditions conducive to
optimal waterfowl nesting and observations of pair crowding on remaining stock
ponds and creeks with little shoreline vegetation supported the general assessment
of poor conditions. The northeastern portion of the stratum near Plentywood
showed good habitat with most basins full or nearly so and adequate emergent and
upland vegetation. This contrasted sharply with the western strata which showed
very dry conditions including dry stream beds and basins and though extensive
acreage of CRP land was present, little adjacent water was observed for
waterfowl. The immediate eastern slope of the front range showed some
improvement in conditions with many ponds and particularly extensive systems of
meandering stream drainage supported by snow melt rather then precipitation.
Overall, current observations in stratum 41 indicate below average nesting
conditions which, in turn, portend poor production.
Stratum 42 (South of the Missouri River)
This stratum showed a general gradation of habitat conditions from poor in the
west improving to good in the east near Miles City and points southeast. A
situation similar to that encountered in stratum 41 exists in the areas on the east
slope of the front range which are fed by run off; exhibiting good conditions but
moving east basins rapidly become dry and evidence of crowding and likely non-nesting
birds persist until conditions again improve in the southeast. In these
areas stock ponds and natural basins show adequate water as well as adjacent
upland vegetation for nesting, including tracts of adjacent CRP land. The area
north of Glendive and south of Culbertson was very dry but improving to the
north. Nest initiation is predicted to be below normal with average to below
average success expected for those pairs that do initiate nesting.
Breeding Population Estimates
Aerial and ground observations indicated that survey timing was appropriate with pairs
established on territories and little evidence of transient flocks. By the end of the survey
increasing numbers of flocked drakes appeared as expected, but of concern were additional
observations that appeared to be molting flocks of mixed sexes. This, leading to the concern that
due to the drought and crowding conditions on available ponds, these flocks of mixed sex birds
indicated a portion of the population that would forego nesting this year.
Population estimates of dabblers totaled 715,700 in 2001, a slight increase (6.3%) over 2000
estimates but 34% below the 10-year mean and 17.5% below the long term mean (Table 1). This
trend was consistent for all species with the exception of mallard and American wigeon which
showed declines from 2000 estimates as well as declines from 10-year and long term means. Of
the dabbler species, American wigeon populations showed the largest decline from 2000 (-28%),
and from the 10-year mean (-54%). Only gadwall indicated an increase from the long term mean
(55%), a trend consistent over the last several years (Appendix 1).
Total diving duck population estimates increased 71% from 2000 and showed increases of 36%
and 13.5% over the 10 year and long term means. Considerable trend variations exist between
diver species in these strata largely due to generally low overall densities. An example is
canvasback which show a 30% decrease from the 10-year mean however the expanded
population estimate is only 6500 birds. Ruddy ducks appeared to be doing quite well with large
increases over 2000 estimates, and 10-year and long term mean values, however this is a false
increase, due mainly to a couple of atypical flock observations that inflated the breeding
population estimate. Though not included in diver estimates, mergansers showed a 33.5 %
increase from 10-year mean and a greater than 100% increase from the long term mean.
Canada goose estimates decreased only slightly from the previous year (-7%), nearly matched the
10-year mean, and as expected showed an increase (65%) over the long term mean.
The 2001 population index for American coot declined from the previous year by 69%. Coot
numbers were also below the 10-year mean by 63% and the long term mean by 67%. As coot are
an indicator of the quality and stability of ponds, this data lends further credence to the
observation that 2001 was an abnormally dry year.
Population estimates for most species were divided equally between stratum 41 and 42 with
exceptions in gadwall and coot. Both species were observed in significantly greater numbers in
stratum 41.
Trend graphs #1 through #26 provide a visual depiction of trends in population estimates over
long term.
Conclusions:
As in other years, habitat conditions for stratum 41 and 42 are somewhat mosaic with a general
trend of poor conditions in the western half improving to good conditions in large sections of the
eastern 1/3. Basins in the northwest portions were dry and stream beds were left non-flowing.
Existing water showed evidence of pressure from livestock with degraded adjacent upland cover.
In what would be considered a wet year this area has potential for considerable waterfowl
production however given the current drought conditions overall production is likely to be below
average. The eastern 1/3 of the combined strata contained habitats much better suited to
successful nesting and brood survival. The southeast and northeast portions displayed lush
upland cover, filled basins, larger stream systems, and many older dugout impoundments which
have taken on characteristics of natural ponds as far as shoreline and aquatic vegetation. Overall,
pond numbers decreased considerably from 10 year and long term means. Dabbler numbers
mirrored this trend with similar reductions from mean values. While the eastern portions of the
survey unit may provide for normal waterfowl production it may not make up for the dry
conditions in the western half and overall production in this survey unit is expected to be below
average.
Table 1. Status of waterfowl breeding population estimates (thousands, adjusted for visibility bias) by species and
stratum with comparison against the previous year, the previous 10-year mean, and the long-term mean for Montana.
Stratum % Change From
Species/Ponds 41 42 2001
Total
2000
Total
10-Year
Mean
Long-
Term
Mean
2000 10-Year
Mean
Long-
Term
Mean
Ducks
Dabblers
Mallard 132.2 107.0 239.1 304.1 368.7 293.7 -21.4% -35.1% -18.6%
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Gadwall 124.2 54.9 179.0 125.9 225.4 115.3 42.2% -20.6% 55.2%
Am. wigeon 23.3 18.3 41.6 57.6 91.5 85.0 -27.8% -54.5% -51.1%
Am. green-winged teal 9.7 8.3 18.1 16.5 27.2 21.4 9.3% -33.8% -15.8%
Blue-winged teal 43.8 29.0 72.8 50.0 125.2 99.0 45.7% -41.9% -26.5%
N. shoveler 53.5 32.6 86.1 60.3 115.2 91.7 42.8% -25.2% -6.1%
N. pintail 53.4 25.6 79.0 58.7 129.4 161.6 34.5% -38.9% -51.1%
Subtotal 440.0 275.8 715.7 673.1 1082.7 867.7 6.3% -33.9% -17.5%
Divers
Redhead 4.8 0.0 4.8 1.8 5.1 5.9 164.3% -5.9% -18.8%
Canvasback 1.2 3.3 4.5 3.5 6.5 5.5 30.0% -30.3% -18.2%
Scaups 19.3 12.2 31.5 30.7 25.9 37.3 2.5% 21.6% -15.7%
Ring-necked duck 2.9 0.0 2.9 0.0 2.5 2.4 -- 16.7% 24.5%
Goldeneyes 0.0 0.0 0.0 0.5 0.6 0.8 -100.0% -100.0% -100.0%
Bufflehead 0.6 0.0 0.6 1.7 1.1 1.5 -63.2% -43.8% -56.5%
Ruddy Duck 20.4 4.5 24.9 2.4 9.3 7.7 959.4% 166.9% 225.0%
Subtotal 49.3 20.0 69.3 40.6 51.1 61.0 70.8% 35.7% 13.5%
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.1 0.0 -- -100.0% -100.0%
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Scoters 0.0 0.0 0.0 0.0 0.1 0.0 -- -100.0% -100.0%
Mergansers 1.2 3.5 4.8 6.7 3.6 2.3 -28.9% 33.5% 109.1%
Subtotal 1.2 3.5 4.8 6.7 3.7 2.3 -28.9% 28.6% 104.8%
Total Ducks 490.5 299.3 789.8 720.4 1137.4 931.1 9.6% -30.6% -15.2%
Canada Goose 48.5 39.8 88.2 94.9 88.9 53.3 -7.0% -0.7% 65.5%
Am. coot 20.4 1.2 21.6 69.1 59.2 65.6 -68.8% -63.5% -67.1%
Ponds 74.2 79.7 154.0 162.6 306.3 264.4 -5.3% -49.7% -41.8%
Table 2. Long-term trend in adjusted May pond estimates (thousands) by stratum with
comparisons against the previous year, the previous 10-year mean, and the long-term mean for
Montana.
Stratum
Year 41 42 Total
1974 142.4 66.9 209.2
1975 150.6 128.8 279.4
1976 109.3 126.3 235.5
1977 70.4 88.2 158.6
1978 145.7 156.2 301.9
1979 135.0 106.2 241.2
1980 77.9 74.4 152.3
1981 103.3 73.0 176.3
1982 147.1 126.5 273.5
1983 85.2 88.7 173.9
1984 88.6 117.5 206.2
1985 127.3 160.0 287.3
1986 190.4 206.3 396.7
1987 102.2 127.1 229.3
1988 78.3 92.0 170.3
1989 160.5 177.3 337.8
1990 121.7 124.3 246.0
1991 111.6 130.1 241.6
1992 95.6 140.0 235.5
1993 94.3 100.5 194.8
1994 227.4 251.1 478.5
1995 164.1 184.7 348.8
1996 209.4 174.7 384.1
1997 154.3 160.2 314.5
1998 149.4 176.0 325.4
1999 227.6 149.8 377.3
2000 74.6 88.0 162.6
2001 74.2 79.7 154.0
10-year Mean 150.8 155.5 306.3
Long-term Mean 131.3 133.1 264.4
Percent Change:
From 2000 -0.4% -9.4% -5.3%
From 10-year Mean -50.8% -48.7% -49.7%
From Long-term Mean -43.4% -40.1% -41.8%
Appendix 1. Long-term trend in adjusted waterfowl breeding population estimates (thousands).
Species/Ponds 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974
Ducks
Dabblers
Mallard 363.3 489.4 320.9 198.5 291.3 311.5 273.9 374.2 261.3 198.2
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 147.9 130.5 100.0 93.7 94.3 53.3 49.1 15.5 11.8 69.6
Am. wigeon 36.8 43.2 63.6 68.6 85.8 92.6 58.3 129.8 99.2 76.8
Am. green-winged teal 22.5 18.4 29.9 20.5 8.6 28.2 11.5 31.7 51.5 21.9
Blue-winged teal 137.5 133.3 82.9 53.2 149.9 99.3 87.1 17.0 8.5 77.7
N. shoveler 65.7 83.1 98.6 78.0 109.6 64.9 65.5 61.1 47.2 58.1
N. pintail 287.4 262.9 277.3 72.2 156.4 191.2 124.3 240.6 167.7 116.8
Subtotal 1061.2 1160.7 973.1 584.9 895.9 840.9 669.7 870.0 647.3 619.2
Divers
Redhead 2.6 4.2 12.4 1.4 2.6 2.0 2.4 0.0 2.4 1.0
Canvasback 3.1 0.5 1.6 3.5 5.5 3.6 5.6 6.7 9.6 1.3
Scaups 27.8 44.7 43.0 27.0 50.0 33.2 15.6 39.5 49.2 35.8
Ring-necked duck 3.3 0.9 7.4 2.9 0.2 0.0 0.0 0.0 0.0 2.1
Goldeneyes 0.0 1.3 0.0 0.0 0.6 0.0 0.0 8.8 2.4 0.0
Bufflehead 1.3 1.3 0.4 2.1 1.4 0.4 0.0 1.7 0.6 1.7
Ruddy Duck 0.0 2.7 1.7 1.5 22.3 0.6 1.3 5.7 3.1 1.8
Subtotal 38.1 55.7 66.4 38.3 82.7 39.9 25.0 62.4 67.4 43.8
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 1.4 0.0 7.7 0.7 0.0 0.0 0.0 0.7 0.8 3.5
Subtotal 1.4 0.0 7.8 0.7 0.0 0.0 0.0 0.7 0.8 3.5
Total Ducks 1100.7 1216.4 1047.3 623.9 978.6 880.8 694.6 933.1 715.5 666.6
Canada Goose 19.0 0.0 44.9 42.2 42.2 50.4 61.2 31.6 14.0 22.1
Am. coot 13.9 19.4 23.4 58.1 31.0 22.3 9.6 17.5 38.0 22.2
Ponds 209.2
Species/Ponds 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984
Ducks
Dabblers
Mallard 478.4 168.0 171.0 282.5 258.3 256.2 245.8 323.5 230.1 189.8
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 72.9 55.3 19.7 174.8 78.6 83.5 119.9 95.1 71.0 38.3
Am. wigeon 110.6 99.7 77.1 157.0 87.9 148.9 65.2 89.4 77.9 73.0
Am. green-winged teal 53.1 13.6 3.9 18.2 40.1 9.9 9.1 13.4 18.9 10.6
Blue-winged teal 98.3 207.1 93.8 93.9 117.5 103.4 81.8 211.0 79.9 52.1
N. shoveler 100.2 102.2 31.1 179.2 189.6 52.2 121.8 160.7 61.8 65.0
N. pintail 259.2 226.0 118.5 348.9 324.8 146.6 157.3 306.9 88.3 99.8
Subtotal 1172.8 871.9 514.9 1254.7 1096.7 800.7 801.0 1200.0 627.9 528.6
Divers
Redhead 0.7 2.7 3.2 7.0 14.7 4.4 25.0 15.0 10.5 19.2
Canvasback 2.1 16.2 3.2 6.4 10.4 4.8 5.4 12.5 5.0 3.5
Scaups 26.4 29.9 34.4 72.1 88.6 36.8 35.8 61.0 47.1 53.3
Ring-necked duck 0.0 1.4 0.2 0.8 0.0 0.9 0.9 2.4 16.3 3.0
Goldeneyes 0.0 0.0 0.6 0.0 1.1 1.6 0.0 0.0 0.0 0.6
Bufflehead 0.4 0.6 0.0 1.3 3.6 1.0 2.4 5.6 0.4 1.8
Ruddy Duck 2.6 1.9 1.2 14.1 12.4 0.7 17.1 17.8 9.1 11.8
Subtotal 32.2 52.7 42.8 101.7 130.8 50.1 86.6 114.2 88.3 93.1
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.0
Mergansers 1.4 0.8 2.7 1.9 4.1 0.0 8.5 1.8 0.0 1.4
Subtotal 1.4 0.8 2.7 1.9 4.1 0.0 8.5 1.8 0.2 1.4
Total Ducks 1206.4 925.4 560.3 1358.3 1231.5 850.8 896.0 1316.0 716.5 623.1
Canada Goose 23.1 27.0 26.3 27.9 41.6 36.6 31.3 37.1 34.6 51.1
Am. coot 13.8 59.5 16.4 83.1 319.4 104.2 197.7 53.3 42.9 103.5
Ponds 279.4 235.5 158.6 301.9 241.2 152.3 176.3 273.5 173.9 206.2
Appendix 1 (continued). Long-term trend in adjusted waterfowl breeding population estimates (thousands).
Species/Ponds 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994
Ducks
Dabblers
Mallard 152.0 156.9 240.9 218.0 282.8 148.4 222.7 239.9 288.6 368.7
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 40.8 33.8 32.6 30.7 128.5 56.7 96.9 154.4 181.5 182.9
Am. wigeon 58.7 52.0 64.9 44.0 58.8 126.2 70.3 88.2 65.5 137.7
Am. green-winged teal 6.4 6.2 6.0 12.0 17.0 15.7 12.4 16.3 8.4 34.0
Blue-winged teal 38.6 21.6 40.2 83.5 65.9 76.3 77.7 89.0 60.3 186.4
N. shoveler 34.1 69.3 73.2 33.7 58.6 86.3 51.5 27.1 92.7 194.3
N. pintail 56.5 95.9 146.0 61.6 58.0 131.2 43.1 75.5 130.4 244.5
Subtotal 387.0 435.6 603.8 483.6 669.6 640.6 574.7 690.4 827.4 1348.5
Divers
Redhead 2.7 3.6 3.4 2.7 7.0 7.8 6.4 5.5 5.3 3.4
Canvasback 2.1 2.8 1.0 2.1 5.1 10.8 1.0 5.6 9.3 12.5
Scaups 20.0 33.4 44.7 55.9 46.9 33.1 25.2 14.0 28.3 28.6
Ring-necked duck 4.3 7.1 0.4 1.2 3.8 0.4 0.5 3.9 4.0 5.0
Goldeneyes 1.3 2.5 0.0 0.0 1.1 0.6 0.7 0.0 1.5 0.0
Bufflehead 1.0 0.4 0.0 4.1 1.7 6.0 2.2 1.3 0.4 0.3
Ruddy Duck 8.0 4.6 0.6 25.1 5.8 9.2 38.0 9.2 1.8 4.7
Subtotal 39.3 54.5 50.2 91.2 71.4 67.9 73.9 39.6 50.6 54.5
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.7 2.8 1.9 1.4 2.1 0.0 4.2 1.3 1.0 0.8
Subtotal 0.7 2.8 1.9 1.4 2.1 0.0 4.2 1.3 1.0 0.8
Total Ducks 427.1 492.9 656.0 576.2 743.1 708.6 652.8 731.3 879.0 1403.7
Canada Goose 49.4 32.9 39.4 67.1 79.3 97.7 70.8 90.5 103.3 76.3
Am. coot 145.2 32.1 27.2 95.5 65.9 153.4 52.9 15.3 58.3 56.8
Ponds 287.3 396.7 229.3 170.3 337.8 246.0 241.6 235.5 194.8 478.5
Species/Ponds 1995 1996 1997 1998 1999 2000 2001
Ducks
Dabblers
Mallard 366.0 386.9 641.2 549.5 319.0 304.1 239.1
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 359.3 201.7 513.5 232.7 205.3 125.9 179.0
Am. wigeon 116.9 100.2 122.4 92.9 63.1 57.6 41.6
Am. green-winged teal 30.3 56.1 58.1 13.3 27.2 16.5 18.1
Blue-winged teal 94.4 89.3 138.1 225.5 241.5 50.0 72.8
N. shoveler 81.4 109.3 209.1 90.5 235.6 60.3 86.1
N. pintail 154.5 135.6 209.3 110.9 131.8 58.7 79.0
Subtotal 1202.8 1079.1 1891.7 1315.4 1223.5 673.1 715.7
Divers
Redhead 3.4 8.1 4.3 6.1 6.3 1.8 4.8
Canvasback 8.0 4.6 9.6 6.1 4.9 3.5 4.5
Scaups 21.4 35.9 32.7 14.1 28.0 30.7 31.5
Ring-necked duck 7.0 0.4 0.0 2.1 2.4 0.0 2.9
Goldeneyes 0.4 0.0 0.9 0.7 1.4 0.5 0.0
Bufflehead 0.5 0.0 2.2 1.5 1.1 1.7 0.6
Ruddy Duck 7.0 1.2 8.9 11.8 8.3 2.4 24.9
Subtotal 47.7 50.1 58.6 42.4 52.5 40.6 69.3
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.5 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.3 0.5 0.0 0.0 0.0 0.0
Mergansers 2.6 3.1 1.9 3.0 11.3 6.7 4.8
Subtotal 2.6 3.4 2.4 3.0 11.8 6.7 4.8
Total Ducks 1253.1 1132.6 1952.7 1360.8 1287.9 720.4 789.8
Canada Goose 98.6 106.6 78.5 84.9 84.2 94.9 88.2
Am. coot 33.2 38.8 80.1 12.8 174.7 69.1 21.6
Ponds 348.8 384.1 314.5 325.4 377.3 162.6 154.0
 
 
 
    
  
 
  
  
  
 
 
 
 
 
  
   
   
   
  
 
  
 
 
   
 
  
 
 
    
   
 
  
 
  
    
  
  
  
   
        
        
        
 
 
  
   
 
   
   
      
  
  
  
      
  
  
   
 
 
   
    
  
 
 
 
 
  
 
 
 
  
 
 
 
   
       
  
 
 
  
  
  
   
 
   
 
 
Poor
Fair
Good
Excellent
  
  
Figure 1. Preliminary breeding waterfowl habitat conditions during May 2001, as judged by U.S. Fish & Wildlife Service Flyway Biologists.
Strata 41-42 Mergansers
Population
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Mallard
Population
100000
200000
300000
400000
500000
600000
700000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 American black duck
Population
0
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Gadwall
Population
0
100000
200000
300000
400000
500000
600000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 American wigeon
Population
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
160000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 American green-winged teal
Population
0
10000
20000
30000
40000
50000
60000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Blue-winged teal
Population
0
100000
200000
300000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Northern shoveler
Population
0
100000
200000
300000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Northern pintail
Population
0
100000
200000
300000
400000
500000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Redhead
Population
0
10000
20000
30000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Canvasback
Population
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
13000
14000
15000
16000
17000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Scaups
Population
10000
20000
30000
40000
50000
60000
70000
80000
90000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Ring-necked duck
Population
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
13000
14000
15000
16000
17000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Goldeneyes
Population
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Bufflehead
Population
0
1000
2000
3000
4000
5000
6000
7000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Oldsquaw
Population
0
100
200
300
400
500
600
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Common Eider
Population
0
Year
1950 1960 1970 1980 1990 2000
Strata 41-42 Scoters
Population
0
100
200
300
400
500
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Ruddy Duck
Population
0
10000
20000
30000
40000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Canada Goose
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 American coot
Population
0
100000
200000
300000
400000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Ponds
Population
100000
200000
300000
400000
500000
Year
1970 1980 1990 2000 2010
Strata 41-42 Dabblers
Population
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
1600000
1700000
1800000
1900000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Divers
Population
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Miscellaneous
Population
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 41-42 Total Ducks
Population
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
1600000
1700000
1800000
1900000
2000000
Year
1950 1960 1970 1980 1990 2000 2010