The 2005 North American trumpeter swan survey

              The 2005
North American
Trumpeter Swan
Survey
U.S. Fish & Wildlife Service
April 2006
Compiled by T. J. Moser
U.S. Fish and Wildlife Service
Division of Migratory Bird Management
Denver, Colorado
The 2005 North American
Trumpeter Swan Survey
A Cooperative North American Survey
Abstract: The abundance and productivity of North American trumpeter swans (Cygnus buccinator) was
assessed during the 2005 quinquennial trumpeter swan survey, May 2005-January 2006. The
continental estimate of trumpeter swan abundance in 2005 was 34,803, a record-high level since
comprehensive surveys were initiated in 1968, and 47% higher than the estimate during the 2000 survey.
Abundance estimates for each of North America’s 3 recognized trumpeter swan populations also reached
record-high levels during the 2005 survey. Survey biologists estimated that the Pacific Coast Population
included 24,928 swans, 42% more than during the 2000 survey. The abundance estimate of Rocky
Mountain Population swans during the 2005 survey was 5,228 birds, 43% higher than in 2000. The 2005
survey estimate for the Interior Population was 4,647 swans, an increase of 91% from the estimate in
2000. The age distributions of all swan populations during the 2005 survey ranged from 27% to 31%
cygnets, and were higher than the 2000 percentage for each population. We present estimates of
average annual growth rates and indices of production for these populations and their component flocks.
INTRODUCTION
Quinquennial trumpeter swan surveys are intended to provide comprehensive assessments of swan
abundance and indices of swan productivity throughout the entire breeding ranges of the 3 recognized
North American populations: the Pacific Coast, Rocky Mountain, and Interior populations (Fig. 1). These
systematic and cooperative surveys of North American trumpeter swans were first conducted in 1968,
repeated in 1974-75, and continued at 5-year intervals thereafter (1980-2005). Survey coverage was
expanded in 1985 and considered comprehensive, but survey coverage has continued to change in
response to population restoration efforts and changes in swan distribution. This report summarizes
results of the 2005 North American trumpeter swan survey and compares these data with previous
quinquennial survey results (Caithamer 2001).
METHODS
Cooperating observers were requested to assess the abundance and productivity of wild trumpeter swans
that were present during the breeding season throughout each survey region. Late summer was the
targeted survey period, but some regions delayed efforts until winter to allow swans to congregate from
dispersed breeding areas within regions. No efforts were directed at surveying captive swans in 2005.
Survey biologists counted trumpeter swans in each of 2 age classes (cygnet or adult/subadult), and
adult/subadult swans were separated into 5 social groups (paired with cygnets, paired without cygnets,
single without cygnets, single with cygnets, or members of flocks).
All population estimates were treated as though they were measured without error. Trends in abundance
estimates for populations and flocks over the long term (generally 1968-2005) and the last 2 survey periods
(2000 and 2005) were calculated through regression of the natural logarithm of survey estimates on year. The
estimated annual growth rates (regression slopes) from the long-term regressions were tested for equality to
zero (t-test). The alpha level (P value) used for determining statistical significance was 0.10. In some regions,
wild swan populations have been supplemented through restoration releases; in these cases growth rates may
overestimate intrinsic growth. Mean brood sizes were calculated by weighting averages from various reporting
areas. Temporal trends in the age distributions of flocks were evaluated through linear regression.
Adult/subadult (“white”) swans for which social status was not determined were excluded from calculation of
social group distribution.
Population and flock terminology in this report follows population-specific management plans
(Subcommittee on the Interior Population of Trumpeter Swans 1998, Pacific Flyway Council 2002, 2006).
Most trumpeter swan reporting regions named in this report can be adequately located using their
geographic titles and Figure 1, but additional descriptions for some regions are provided here. Tri-state
Area Flock swans nest in southeastern Idaho, southwestern Montana, and western Wyoming; Canadian
1
Rocky Mountain Population swans nest in this population’s range in Canada; and swans in Other U.S.
flocks nest within the remaining Rocky Mountain Population range. High Plains Interior Population swans
nest from the Rocky Mountain Population’s eastern boundary to the western borders of Ontario,
Minnesota, and Iowa; Mississippi and Atlantic Flyway swans nest from the last-mentioned borders
eastward.
During 2005, managers of Pacific Coast Population trumpeter swans in the Yukon and British Columbia
region reconciled historical datasets which prompted slight revision (<4 swans per year) of PCP
abundance estimates from previous quinquennial surveys. The reconciled estimates are included in this
report and therefore differ slightly from those within previous quinquennial reports.
The 2005 trumpeter swan survey was conducted by numerous individuals and agencies throughout North
America between 15 May 2005 and 7 January 2006 (see Appendix A for these dates and other 2005 raw
data). The median starting and ending dates for the 2005 survey were 24 August and 14 September,
respectively. For comparison, the 2000 survey was conducted 15 April to 25 January with median
starting and ending dates of 20 August and 11 September, respectively. Most areas were surveyed
aerially or by a network of ground observers similar to efforts during the 2000 survey with 1 exception.
Due to warm temperatures and wide dispersal of swans in Minnesota during 2005, the formal survey was
not conducted. Minnesota estimates for the 2005 survey were based on periodic ground counts from
spring through mid-winter. Generally, survey results in 2005 were believed to be complete censuses,
except for northern British Columbia and the Yukon Territory where swan estimates were based on
stratified random sample of mapsheets across the probable range of trumpeter swans.
RESULTS
North American Trumpeter Swans
During the 2005 trumpeter swan survey the estimated abundance of all North American trumpeter swans
was 34,803, 47% higher than the estimate from the 2000 survey (23,647), and a record-high level since
surveys began in 1968 (Tables 1-2, Fig. 2). These data suggest North America’s trumpeter swan
population increased an average of 7.7% each year during 2000-2005. The estimated rate of growth
during 1968-2005 was +6.0% per year (P < 0.0001, Table 2). Abundance estimates from the 2005
survey reached record-high levels for each of the 3 recognized populations (see population-specific
sections below).
During the 2005 survey 28% of all trumpeter swans observed were cygnets, the third highest proportion
on record (1968-2005, Table 3), and a higher proportion than observed during the 2000 survey (22%).
Analysis indicated no long-term trend in the percentage of the population comprised of cygnets (Fig. 3, P
= 0.33). The average brood size in 2005 was 3.10 cygnets, slightly higher than the 2000 value of 3.0.
Survey observers in 2005 indicated trumpeter swans had expanded their range since the 2000 survey in
all 4 directions from previously reported range in Alaska, along the Mackenzie River in the Northwest
Territories, and to small areas adjacent to the previous range in Alberta, western Wyoming, eastern
Saskatchewan, western Manitoba, and southeastern Michigan (Fig. 1).
Pacific Coast Population (PCP)
Abundance estimates of all PCP swans reached a record-high level of 24,928 in 2005, 42% higher than in
2000 (Tables 1-2, Fig. 4). Estimated annual growth rates during 2000-2005 and 1968-2005 averaged
+7.0% and +5.8%, respectively (Table 2). In 2005, 27% percent of PCP swans observed were cygnets,
higher than in 2000 (19%) and slightly higher than the 1968-2000 average of 26% (Table 3). Analysis
showed little indication of a long-term trend in the age distribution of the population (Fig. 3, P = 0.19).
Average brood size for PCP swans in 2005 was 3.1 cygnets, somewhat higher than in 2000 (2.8).
The abundance estimate of the Alaska flock in 2005 was 23,692 swans, a record-high level and 38%
2
higher than in 2000 (Tables 1-2). The 2005 estimate of Yukon and northwest British Columbia flock
swans was 1,236 (95% CI = 1,114–1,358), also a record high, and 211% higher than in 2000. Additional
flock information is provided in Tables 1-4.
Rocky Mountain Population (RMP)
The 2005 survey yielded an estimate of 5,228 RMP trumpeter swans, which was 43% higher than the
2000 estimate, and the highest estimate on record (Tables 1-2, Fig. 5). Estimated average annual growth
rates during 2000-2005 and 1968-2005 were +7.1% and +5.4%, respectively. The proportion of observed
swans that were cygnets in 2005 was 30%, the same proportion as in 2000, and higher than the 1968-
2000 average of 25% (Table 3). Linear regression indicates an increasing trend in the percentage of
cygnets in the RMP population during 1968-2005 (+0.33% per year, P = 0.07, Fig. 3). Brood sizes in
2005 averaged 3.0 cygnets, slightly lower than in 2000 (3.1).
During the 2005 survey, the RMP Canadian flocks were estimated to include 4,718 swans, 48% more
than in 2000, and the most recorded since 1968 (Tables 1-2). In 2005, there were 453 swans counted in
the Tri-state Area Flock, 6% more than in 2000, but fewer than the peak count of 589 in 1990. Although
swan abundance in the Tri-state Area Flock remains below the levels of 1968-1990, quinquenniel survey
abundance estimates have increased consecutively from 1995 through 2005 (Table 2). The 2005 survey
estimated a population of 57 swans in Other U.S. flocks, 1 bird more than observed in 2000. Other U.S
flocks are the only regional group that showed significant decline during the 1968-2005 period (-2.6% per
year, P = 0.02). Additional flock information is provided in Tables 1-4.
Interior Population (IP)
The 2005 survey indicated a record-high estimate of 4,647 IP swans, an increase of 91% over the 2000
estimate (Tables 1-2, Fig. 6). The IP exhibited the highest average annual growth rate of the 3 trumpeter
swan populations, +13.0% during 2000-2005, and +11.7% during 1968-2005. In 2005, 31% percent of IP
swans observed were cygnets, similar to the proportion in 2000 and the 1968-2000 average (30% and
29%, respectively; Table 3). The age distribution of the population indicated no long-term trend in the
proportion of cygnets (Fig. 3, P = 0.67). Average brood size in 2005 was 3.2 cygnets, lower than the
value of 3.6 from the 2000 survey.
The 2005 abundance estimate for Mississippi and Atlantic Flyway trumpeter swans was 4,176 swans,
103% higher than in 2000, and the highest estimate on record. The High Plains flock estimate was 471
swans in 2005, 27% higher than in 2000, and a record-high estimate. Additional flock information is
provided in Tables 1-4.
DISCUSSION
Abundance estimates for all North American trumpeter swans and for each of the 3 recognized
populations reached record-high levels during the 2005 survey. Estimated average annual growth rates
for all populations exceeded 5% (range: 5.4-11.7%) over the long term and 7% (range: 7.0-7.7%)
between 2000 and 2005 (Table 2). Additionally, abundance estimates for each of the 7 swan flocks was
higher during the 2005 survey than in 2000, although increases for the Tri-state Area and Other U.S.
RMP flocks were small. With the exception of Tri-state Area and Other U.S. RMP flocks, estimated
annual growth rates for flocks exceeded 4.8% (range: 4.8-23.7%) over the long term and 4.9% (range:
4.9-22.7%) between 2000 and 2005. These growth rates include the effects of swan releases associated
with restoration efforts. Only the Tri-state Area and Other U.S. flocks of the RMP exhibited negative
growth over the long-term period and showed only slight growth between 2000 and 2005. A more
detailed evaluation of population status of these flocks is available (U.S. Fish and Wildlife Service 2005,
2006).
Comparison of abundance estimates from the 2005 quinquennial trumpeter swan survey with numerical
goals contained within current management plans for these populations indicate that substantial
3
accomplishments have been made (Subcommittee on the Interior Population of Trumpeter Swans 1998,
Pacific Flyway Council 2002, 2006). The PCP objective is to maintain “not less than 25,000 swans” as
measured by quinquennial surveys, compared with the 2005 estimate of 24,929 swans. The RMP
management plan goal is “a 5% average annual growth in the number of wintering birds.” The short-term
and long-term growth rates from the summer/fall quinquennial survey data (7.1% and 5.4%, respectively)
would appear to support that goal. However, the RMP plan also contains several flock-specific objectives
which have not yet been achieved. The number of IP swans exceeded the management plan’s principal
population objective of “at least 2,000 birds and 180 successful breeding pairs by 2001” by the time of the
2000 quinquennial survey (2,430 swans and 203 broods [Caithamer 2001]). While significant
accomplishments have been made towards reaching goals for all 3 populations, it is noted that each
management plan includes additional goals or objectives that have not been achieved.
For all 3 North American trumpeter swan populations, growth rates during 2000-2005 exceeded the
average growth rates during 1968-2005 (Table 2) and 1968-2000 (6.0%, 5.0%, and 10.9% for the PCP,
RMP, and IP, respectively). No population exhibited a significant decline in the proportion of cygnets
composing the surveyed population over the period of survey (P-values for any negative trends were
greater than 0.19). Notwithstanding challenges regarding swan habitats and migratory behaviors,
prospects for continued growth of North America’s trumpeter swan populations appear promising.
ACKNOWLEDGMENTS
Data for the 2005 North American trumpeter swan survey were collected by numerous individuals
employed by many agencies, volunteers, and citizens who reported incidental swan observations. The
compiler apologizes for any cooperators omitted from Appendix B. Regional surveys were coordinated or
summarized by B. Bales, G. Beyersbergen, B. Bortner, A. Breault, S. Comeau-Kingfisher, B. Conant, J.
Cornely, J. Dubovsky, D. Groves, C. Harris, J. Hawkings, D. Hoffman, T. Hogrefe, J. Johnson, S.
Kittelson, H. Lumsden, S. Matteson, D. Sherman, and B. Swift. The cooperation of Canadian Wildlife
Service and the Trumpeter Swan Society was integral to survey completion. R. Oates, R. Trost, and B.
Millsap helped secure and administer Fish and Wildlife Service funding for the 2005 survey. The cover
photograph was provided by J. Cornely. J. Dubovsky, M. Koneff, R. Shea, and K. Wilkins provided
helpful comments on earlier drafts of this report.
LITERATURE CITED
Caithamer, D. F., compiler. 2001. Trumpeter swan population status, 2000. U.S. Fish and Wildlife
Service. Washington, D.C.
U.S. Fish and Wildlife Service. 2005. Trumpeter swan survey of the Rocky Mountain Population, U.S.
Breeding Segment – Fall 2005. U.S. Fish and Wildlife Service report. Denver, Colorado.
U.S. Fish and Wildlife Service. 2006. Trumpeter swan survey of the Rocky Mountain Population –
Winter 2006. U.S. Fish and Wildlife Service report. Denver, Colorado.
Subcommittee on the Interior Population of Trumpeter Swans. 1998. Mississippi and Central Flyway
Management Plan for the Interior Population of Trumpeter Swans. Mississippi and Central
Flyway Councils [c/o U.S. Fish and Wildlife Service]. Twin Cities, Minnesota.
Pacific Flyway Council. 2006. Pacific Flyway management plan for the Pacific Coast Population of
Trumpeter Swans. Pacific Flyway Study Committee [c/o U.S. Fish and Wildlife Service].
Portland, Oregon.
Pacific Flyway Council. 2002. Pacific Flyway management plan for the Rocky Mountain Population of
Trumpeter Swans. Pacific Flyway Study Committee [c/o U.S. Fish and Wildlife Service].
Portland, Oregon.
4
Table 1. Demographics of Pacific Coast, Rocky Mountain, and Interior populations of trumpeter swans during the 2005 North American trumpeter
swan survey.
Mean brood size2
Population and flock Total swans White swans1 Cygnets % cygnets Broods x n
Pacific Coast Population
Alaska 23,692 17,245 6,447 27 2,084 3.09 2,084
Yukon and northwestern
British Columbia 1,236 867 369 30 100 3.74 72
Total Pacific Coast Population 24,928 18,112 6,816 27 2,184 3.11 2,156
Rocky Mountain Population
Canadian 4,718 3,270 1,448 31 470 3.03 358
Tri-state Area Flock 453 355 98 22 34 2.81 32
Other U.S. flocks 57 49 8 14 4 2.00 4
Total Rocky Mountain Population 5,228 3,674 1,554 30 508 3.00 394
Interior Population
High Plains 471 362 109 23 41 2.32 41
Mississippi and Atlantic
Flyways 4,176 2,858 1,318 32 219 3.39 219
Total Interior Population 4,647 3,220 1,427 31 260 3.22 260
North American total 34,803 25,006 9,797 28 2,952 3.10 2,810
1 Adult and subadult swans.
2 Weighted mean based on number of broods of known size observed in each survey area.
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Table 2. Estimates of abundance and average annual growth rates of North American trumpeter swans from quinquennial surveys, 1968-20051
Year of survey
Annual
growth
rate
Annual
growth
rate3
Population and flock 1968 1975 1980 1985 1990 1995 2000 2005 2000-2005 1968-2005
Pacific Coast Population
Alaska 2,847 4,170 7,696 9,459 13,337 15,823 17,155 23,692 +6.5% +5.6%**
Yukon and northwestern
British Columbia 41 119 492 397 1,236 +22.7% +16.0%*
Total Pacific Coast Population 2,847 4,170 7,696 9,500 13,456 16,315 17,552 24,928 +7.0% +5.8%**
Rocky Mountain Population
Canadian 106 1312 379 614 1,117 2,076 3,183 4,718 +7.9% +11.1%**
Tri-state Area Flock 585 5372 485 507 589 364 426 453 +1.2% -0.8%
Other U.S. flocks 120 131 111 74 41 77 56 57 +0.3% -2.6%*
Total Rocky Mountain Population 811 7992 975 1,195 1,747 2,517 3,665 5,228 +7.1% +5.4%**
Interior Population
High Plains 64 116 164 158 185 240 370 471 +4.8% +4.9%**
Mississippi and Atlantic
Flyways 0 0 12 51 237 687 2,060 4,176 +14.1% +23.7%**
Total Interior Population 64 116 176 209 422 927 2,430 4,647 +13.0% +11.7%**
North American total 3,722 5,085 8,847 10,904 15,625 19,759 23,647 34,803 +7.7% +6.0%**
1 Estimates for 1968-2000 were from Caithamer (2001). Data for Yukon and nw British Columbia Pacific Coast swans 1985-2000 were revised slightly in 2005 (see methods).
2 Estimates reported in 1975 were obtained in 1974 or 1975.
3 Asterisks denote significance of regression slopes at the following P-values: * = P < 0.05, ** = P < 0.0001.
6
Table 3. Age distribution (percent cygnets) of North American trumpeter swans observed during quinquennial surveys, 1968-20051.
Population and flock 1968 1975 1980 1985 1990 1995 2000 2005
Pacific Coast Population
Alaska 32 28 32 18 27 24 19 27
Yukon and northwestern
British Columbia 15 37 39 26 30
Total Pacific Coast Population 32 28 32 18 27 25 19 27
Rocky Mountain Population
Canadian 29 332 27 30 32 30 32 31
Tri-state Area Flock 26 152 5 27 25 15 24 22
Other U.S. flocks 18 18 31 8 27 14 13 14
Total Rocky Mountain Population 25 182 16 28 30 28 30 30
Interior Population
High Plains 33 30 27 40 34 21 28 23
Mississippi and Atlantic
Flyways 0 14 27 26 30 32
Total Interior Population 33 30 25 33 30 25 30 31
North American total 31 27 30 19 27 25 22 28
1 Estimates for 1968-2000 were from Caithamer (2001).
2 Estimates reported in 1975 were obtained in 1974 or 1975.
7
Table 4. Social status of adult and subadult1 trumpeter swans observed during the 2005 North
American trumpeter swan survey.
Population and flock Paired (%) Single (%) In flocks (%)
Swans
categorized
Pacific Coast Population
Alaska 69.2 6.7 24.1 17,245
Yukon and northwestern
British Columbia 65.1 4.8 30.1 867
Total Pacific Coast Population 69.0 6.6 24.4 18,112
Rocky Mountain Population
Canadian 76.1 5.3 18.6 3,270
Tri-state Area Flock 53.0 7.3 39.7 355
Other U.S. flocks 65.3 2.0 32.7 49
Total Rocky Mountain Population 73.7 5.4 20.9 3,674
Interior Population
High Plains 70.7 6.4 22.9 362
Mississippi and Atlantic Flyways 62.3 3.2 34.5 1,114
Total Interior Population 64.4 4.0 31.6 1,476
North American total 69.5 6.2 24.3 23,262
1Table entries exclude adults for which social status was not determined.
8
Fig. 1. Approximate breeding range of Pacific Coast, Rocky Mountain, and Interior populations of
trumpeter swans. Trumpeter swan range expansion reported by survey biologists during the 2005
North American trumpeter swan survey is shown in red.
9
Year
'68 '75 '80 '85 '90 '95 '00 '05
Total swans
0
5000
10000
15000
20000
25000
30000
35000
All trumpeter swans
Pacific Coast Population
Rocky Mountain
Population
Interior Population
Fig. 2. Total North American and population-specific trumpeter swan abundance estimates resulting from quinquennial trumpeter swan
surveys, 1968-2005.
10
Year
'68 '75 '80 '85 '90 '95 '00 '05
Percent cygnets
10
20
30
40
All trumpeter swans
Pacific Coast Population
Rocky Mountain
Population
Interior Population
Fig. 3. Age distribution (percent cygnets) of North American trumpeter swans observed during quinquennial trumpeter swan surveys, 1968-2005.
11
Year
'68 '75 '80 '85 '90 '95 '00 '05
Total swans
0
5000
10000
15000
20000
25000
Total Pacific Coast Population
Alaska
Yukon & British Columbia
Fig. 4. Pacific Coast Population trumpeter swan abundance estimates resulting from quinquennial trumpeter swan surveys, 1968-2005.
12
Year
'68 '75 '80 '85 '90 '95 '00 '05
Total swans
0
1000
2000
3000
4000
5000
6000
Total Rocky Mountain Population
Canadian
Tri-state Area
Other U.S.
Fig. 5. Rocky Mountain Population trumpeter swan abundance estimates resulting from quinquennial trumpeter swan surveys, 1968-2005.
13
Year
'68 '75 '80 '85 '90 '95 '00 '05
Total swans
0
250
500
750
1000
1250
1500
1750
2000
2250
2500
2750
3000
3250
3500
3750
4000
4250
4500
4750
Total Interior Population
Mississippi and
Atlantic Flyways
High Plains
Fig. 6. Interior Population trumpeter swan abundance estimates resulting from quinquennial trumpeter swan surveys, 1968-2005.
14
Appendix A. Raw data from the 2005 North American trumpeter swan survey.
State or 2005 2005 Total Flocked
Population Flock Region Province start end Method1 Coverage2 Adults Cygnets swans adults Flocks
Pacific Coast Pacific AK AK 20-Jul-05 8-Sep-05 1 1 17245 6447 23692 4148 658
Pacific Coast Pacific YK & n. BC YK & BC 11-Aug-05 20-Aug-05 1 2 868 369 1236 261 60
Rocky Mountain Canadian YK & n. BC YK & BC 11-Aug-05 26-Aug-05 1 2 1194 599 1793 67 15
Rocky Mountain Canadian BC - ne BC 13-Aug-05 18-Aug-05 1 1 438 152 590 66 17
Rocky Mountain Canadian BC - se BC 24-Aug-05 24-Aug-05 1 1 138 51 189 30 6
Rocky Mountain Canadian NWT NWT 24-Aug-05 8-Sep-05 1 1 327 88 415 73 11
Rocky Mountain Canadian AB AB 24-Aug-05 14-Sep-05 1 1 1173 558 1731 374 46
Rocky Mountain Canadian SK SK 5-Jul-05 5-Jul-05 2 1 0 0 0 0 0
Rocky Mountain Tri-state Area MT MT 14-Sep-05 27-Sep-05 1 1 112 40 152 57 7
Rocky Mountain Tri-state Area WY WY 14-Sep-05 15-Sep-05 5 1 107 36 143 29 5
Rocky Mountain Tri-state Area ID ID 16-Sep-05 17-Sep-05 1 1 136 22 158 55 13
Rocky Mountain Other U.S. Ruby Lake NV 14-Sep-05 14-Sep-05 1 1 17 0 17 3 1
Rocky Mountain Other U.S. Malheur OR 19-Sep-05 19-Sep-05 2 1 20 5 25 10 2
Rocky Mountain Other U.S. Summer L. OR 29-Sep-05 29-Sep-05 5 3 3 0 3 3 1
Rocky Mountain Other U.S. OR - other OR 29-Sep-05 29-Sep-05 5 3 9 3 12 0 0
Interior High Plains SD SD 8-Sep-05 10-Sep-05 1 1 73 10 83 39 7
Interior High Plains NE NE 8-Sep-05 10-Sep-05 1 1 211 64 275 31 8
Interior High Plains WY WY 8-Sep-05 10-Sep-05 ? ? 0 0 0 0 0
Interior High Plains MB MB 19-Aug-05 30-Aug-05 1 1 25 10 35 0 0
Interior High Plains SK SK 21-Aug-05 21-Aug-05 1 1 53 25 78 13 4
Interior MS & AT Flyway ON ON 15-May-05 7-Jan-06 5 1 454 190 644
Interior MS & AT Flyway MN MN May4 Mid-winter 2 4 1421 579 2000
Interior MS & AT Flyway WI WI 15-May-05 6-Oct-05 5 1 186 245 431
Interior MS & AT Flyway MI MI 15-Aug-05 30-Nov-05 5 1 540 188 728 249 22
Interior MS & AT Flyway IA IA 26-Sep-05 10-Oct-05 2 1 202 67 269 131 87
Interior MS & AT Flyway OH OH 10-Sep-05 20-Sep-05 5 1 45 46 91 4 1
Interior MS & AT Flyway NY NY 1-Jul-05 15-Sep-05 5 1 10 3 13 0 0
Appendix A. Continued.
Pairs Pairs Singles Singles Mean n for
State or with without Total with without Total brood brood
Population Flock Region Province cygnets cygnets pairs cygnets cygnets broods size size3
Pacific Coast Pacific AK AK 2023 3947 5970 60 1097 2084 3.09 2084
Pacific Coast Pacific YK & n. BC YK & BC 98 184 282 2 40 100 3.74 72
Rocky Mountain Canadian YK & n. BC YK & BC 182 347 529 1 68 183 3.31 71
Rocky Mountain Canadian BC - ne BC 65 108 173 0 26 65 2.38 65
Rocky Mountain Canadian BC - se BC 19 34 53 0 2 19 2.68 19
Rocky Mountain Canadian NWT NWT 37 79 116 0 22 37 2.38 37
Rocky Mountain Canadian AB AB 163 210 373 3 50 166 3.36 166
Rocky Mountain Canadian SK SK 0 0 0 0 0 0 0
Rocky Mountain Tri-state Area MT MT 13 12 25 0 5 15 2.46 13
Rocky Mountain Tri-state Area WY WY 8 23 31 3 13 11 3.27 11
Rocky Mountain Tri-state Area ID ID 8 30 38 0 5 8 2.75 8
Rocky Mountain Other U.S. Ruby Lake NV 0 7 7 0 0 0 0
Rocky Mountain Other U.S. Malheur OR 3 2 5 0 0 3 1.67 3
Rocky Mountain Other U.S. Summer L. OR 0 0 0 0 0 0 0.00 0
Rocky Mountain Other U.S. OR - other OR 1 3 4 0 1 1 3.00 1
Interior High Plains SD SD 5 12 17 0 0 5 2.00 5
Interior High Plains NE NE 25 57 82 2 14 24 2.09 24
Interior High Plains WY WY 0 0 0 0 0 0 0.0
Interior High Plains MB MB 3 7 10 0 5 3 3.33 3
Interior High Plains SK SK 9 10 19 0 2 9 2.78 92
Interior MS & AT Flyways ON ON 50 15 65 1 52 3.80 52
Interior MS & AT Flyways MN MN4
Interior MS & AT Flyways WI WI 68 25 93 68 3.60 68
Interior MS & AT Flyways MI MI 58 77 135 3 18 61 3.08 61
Interior MS & AT Flyways IA IA 20 11 31 1 8 21 3.19 21
Interior MS & AT Flyways OH OH 13 5 18 3 2 16 2.88 16
Interior MS & AT Flyways NY NY 1 4 5 0 0 1 3.00 1
1Survey method (1 = aerial, 2 = ground, 3 = other, 5 = combination of methods).
2Extent of survey coverage (1 = believed complete census, 2 = sample of entire range, 3 = census of part of range).
3Number of broods observed to estimate mean brood size.
4 MN survey not formally conducted in 2005. Estimates are based on periodic ground counts from spring through mid-winter.
Appendix B. Participants and cooperators in the 2005 North American trumpeter swan survey.
Akaran, J. U.S. Fish and Wildlife Service
Anderson, P. U.S. Fish and Wildlife Service
Andrews, R. Iowa Department of Natural Resources
Arbuckle, R. Ducks Unlimited Canada
Ball, G. Manitoba Department of Natural Resources
Barber, J. Ohio Division of Wildlife
Bazin, R. Canadian Wildlife Service
Bertram, M. U.S. Fish and Wildlife Service
Betts, T. National Park Service
Beyersbergen, G. Canadian Wildlife Service
Boersen, M. Michigan Department of Natural Resources
Bogaczyk, B. U.S. Forest Service
Bollinger, K. U.S. Fish and Wildlife Service
Bortner, B. U.S. Fish and Wildlife Service
Brackney, A. U.S. Fish and Wildlife Service
Brazeau Brown, M. Private
Breault, A. Canadian Wildlife Service
Bronson, J. Wisconsin Department of Natural Resources
Bryant, J. U.S. Fish and Wildlife Service
Buchholtz, C. U.S. Fish and Wildlife Service
Cameron, S. Parks Canada Agency
Carey, C. Oregon Department of Fish and Wildlife
Carlson, E. Michigan Department of Natural Resources
Cassinelli, R. U.S. Fish and Wildlife Service
Catterson, N. U.S. Forest Service
Chapman, D. Montana Aircraft, Inc.
Clark, J. Alberta Sustainable Resource Development
Collins, G. U.S. Fish and Wildlife Service
Comeau-Kingfisher, S. U.S. Fish and Wildlife Service
Conant, B. U.S. Fish and Wildlife Service
Corcoran, R. U.S. Fish and Wildlife Service
Cornely, J. U.S. Fish and Wildlife Service
Cozzolino, S. New York Division of Fish, Wildlife, and Marine Resources
Dau, C. U.S. Fish and Wildlife Service
Denison, D. Alpine Aviation
Denton, J. U.S. Bureau of Land Management
Dubovsky, J. U.S. Fish and Wildlife Service
Eckler, J. New York Division of Fish, Wildlife, and Marine Resources
Eckstein, R. Wisconsin Department of Natural Resources
Eldridge, B. U.S. Fish and Wildlife Service
Ellis. J. U.S. Fish and Wildlife Service
Eskowich, K. Ducks Unlimited Canada
Ficht, B. Private
Ficht, J. Alberta Sustainable Resource Development
Fischer, J. U.S. Fish and Wildlife Service
Foerster, S. Catteraquai Conservation Authority
Found, C. Alberta Sustainable Resource Development
Fountain, R. Wye Marsh Wildlife Management Area
Fremmerlid, M. Slave Air
French, R. Michigan Department of Natural Resources
Frey, S. Parks Canada Agency
Appendix B. Continued.
Gibbons, M. Parks Canada Agency
Gingras, B. Canadian Wildlife Service
Gonion, S. U.S. Fish and Wildlife Service
Greene, R. Wisconsin Department of Natural Resources
Grimes, S. U.S. Fish and Wildlife Service
Groves, D. U.S. Fish and Wildlife Service
Guldager, N. National Park Service
Hall, W. Wisconsin Department of Natural Resources
Hans, M. U.S. Fish and Wildlife Service
Hardy, D. Wisconsin Department of Natural Resources
Harrison, B. Ducks Unlimited Canada
Hartley, J. Alberta Public Lands Department
Harwood, C. U.S. Fish and Wildlife Service
Hawkings, J. Canadian Wildlife Service
Hayes, S. Parks Canada Agency
Heckbert, M. Alberta Sustainable Resource Development
Henniger, E. Private
Hobson, D. Alberta Sustainable Resource Development
Hodges, J. U.S. Fish and Wildlife Service
Hoffman, D. Iowa Department of Natural Resources
Hogrefe, T. Michigan Department of Natural Resources
Hopp, J. Wisconsin Department of Natural Resources
Hubbs, A. Alberta Sustainable Resource Development
Huhndorf, J. U.S. Fish and Wildlife Service
Ivey, G. The Trumpeter Swan Society
Johnson, B. Alberta Sustainable Resource Development
Johnson, J. Kellogg Bird Sanctuary
Jozwiak, E. U.S. Fish and Wildlife Service
Kaye, R. Parks Canada Agency
King, J. U.S. Fish and Wildlife Service
King, R. U.S. Fish and Wildlife Service
Kingdon, B. Private
Kittelson, S. Minnesota Department of Natural Resources
Koerner, T. U.S. Fish and Wildlife Service
Kunnas, F. Alberta Sustainable Resource Development
Labrie, G. Slave Air
Larned, B. U.S. Fish and Wildlife Service
Latour, P. Canadian Wildlife Service
Linck, M. Three Rivers Park
Liston, J. Private
Logan, D. U.S. Forest Service
Long, B. Wyoming Wetland Society
Lumsden, H. Ontario Ministry of Natural Resources, retired
Lust, G. Mountain Air Research
MacDougal, K. Parks Canada Agency
Mackay, J. U.S. Fish and Wildlife Service
Mallek, E. U.S. Fish and Wildlife Service
Manthey, P. Wisconsin Department of Natural Resources
Matteson, S. Wisconsin Department of Natural Resources
McEneaney, T. U.S. National Park Service
McIntyre, C. U.S. National Park Service
Appendix B. Continued.
Miller, P. Wisconsin Department of Natural Resources
Mills, T. U.S. Fish and Wildlife Service
Mitchell, C. D. U.S. Fish and Wildlife Service
Mulders, D. Canadian Wildlife Service
Nelson, J. Wisconsin Department of Natural Resources
Niewoonder, J. Michigan Department of Natural Resources
Oates, R. U.S. Fish and Wildlife Service
Oehlers, S. U.S. Forest Service
Olson, D. U.S. Fish and Wildlife Service
Paisley, R. Wisconsin Department of Natural Resources
Parker, M. U.S. Fish and Wildlife Service
Parton, B. New York Division of Fish, Wildlife, and Marine Resources
Patla, S. Wyoming Fish and Game
Paul, C. Allison Air Service
Porter, R. Private landowner Alberta
Pryor, P. Canadian Wildlife Service
Quinlan, R. Alberta Sustainable Resource Development
Racchini, C. U.S. Forest Service
Raynes, B Jackson Hole Bird Club president
Reid, M. National Park Service
Rifleman, R. Private
Rising, G. Private
Roblee, K. New York Division of Fish, Wildlife, and Marine Resources
Rogers, K. U.S. Bureau of Land Management
Roy, R. U.S. Fish and Wildlife Service
Sallows, T. Parks Canada Agency
Schmidt, J. University of Alaska, Fairbanks
Scotton, B. U.S. Fish and Wildlife Service
Shea, R. The Trumpeter Swan Society
Sherman, D. Ohio Division of Wildlife
Simpson, B. Dauphin Air
Simpson, F. Ducks Unlimited Canada
Sitar, K. Michigan Department of Natural Resources
Spindler, M. U.S. Fish and Wildlife Service
Sprenger, J. Wisconsin Department of Natural Resources
Stepniski, D. Alberta Sustainable Resource Development
St. Louis, M. Oregon Department of Fish and Wildlife
Stradley, R. U.S. National Park Service
Swift, B. New York Division of Fish, Wildlife, and Marine Resources
Tate, D. Parks Canada Agency
Terwilliger, M. National Park Service
Tesky, L. Wisconsin Department of Natural Resources
Thompson, P. U.S. Forest Service
Tibbels, A. Ohio Division of Wildlife
Timm, H. U.S. Fish and Wildlife Service
Trost, R. U.S. Fish and Wildlife Service
Visser, L. Michigan Department of Natural Resources
Vivion, M. U.S. Fish and Wildlife Service
Weeks, J. Michigan Department of Natural Resources
Weinfurter, M. Wisconsin Department of Natural Resources
Wilson, H. U.S. Fish and Wildlife Service
Witt, M. Ohio Division of Wildlife
Appendix B. Continued.
Wright, K. Alberta Conservation Association
Wynbrandt, J. Private
Zroback, F. Ontario Ministry of Natural Resources
U.S. Department of the Interior
U.S. Fish & Wildlife Service
April 2006
All Division of Migratory Bird Management reports are available at http://migratorybirds.fws.gov