Trends in duck breeding populations, 1955-2001

              TRENDS IN DUCK BREEDING POPULATIONS, 1955-2001
K. A. Wilkins, M. C. Otto, and P. R. Garrettson
U.S. Fish and Wildlife Service
Division of Migratory Bird Management
11500 American Holly Drive
Laurel, MD 20708-4016
Administrative Reporta – June 29, 2001
This report summarizes preliminary information about the status of duck
populations and their habitats during spring 2001, and focuses on areas encompassed by
the Breeding Waterfowl and Habitat Survey. These numbers are preliminary, and do not
include information from state or provincial surveys. The traditional survey area includes
strata 1-18, 20-50, and 75-77. In the traditional survey area, the total duck population
estimate (excluding scoters [Melanitta spp.], eiders [Somateria and Polysticta spp.], long-tailed
ducks [Clangula hyemalis], mergansers [Mergus and Lophodytes spp.], and wood
ducks [Aix sponsa]) was 36.1 ± 0.6 million birds, 14 % below (P<0.001) last year’s
estimate of 41.8 ± 0.7 million birds, but still 9% above (P<0.001) the 1955-2000 average.
Mallard abundance was 7.9 ± 0.2 million, which is 17% below (P<0.001) last year’s
estimate but similar to (P=0.08) the 1955-2000 average. Blue-winged teal abundance
was estimated at 5.8 ± 0.3 million. This is 23% below (P=0.001) last year’s record
estimate of 7.4 million, but 29% above (P<0.001) the 1955-2000 average. Gadwall (2.7
± 0.1 million, +66%), green-winged teal (2.5 ± 0.2 million, +39%), and northern
shovelers (3.3 ± 0.2 million, +60%) all remained above (P<0.05) their long-term
averages, while American wigeon (2.5 ± 0.1 million), redheads (0.7 ± 0.07 million), and
canvasbacks (0.6 ± 0.05 million) were similar to (P>0.2) their long-term averages. Scaup
numbers (3.7 ± 0.2 million, -31%) were again below the long-term average (P<0.001).
The northern pintail was unchanged compared to 2000 (3.3 ± 0.3 million), but their
numbers remained below the 1955-2000 average (P<0.001).
The eastern survey area is comprised of strata 51-56 and 62-69. The 2001 total
duck population estimate for the eastern survey area was 3.3 ± 0.2 million birds, similar
to last year’s total duck estimate of 3.2 ± 0.3 million birds (P=0.76), and to the 1996-2000
average (P=0.35). Abundances of individual species were similar to those of last year,
a This report is intended for administrative use only and is not for publication without the permission of the
Director, U.S. Fish and Wildlife Service.
with the exception of ring-necked ducks (0.35 ± 0.04 million, P=0.001) and buffleheads
(0.10 ± 0.02 million, P=0.05). Buffleheads (P=0.03), goldeneyes (P=0.08), and lesser
scaup (P=0.08) were above their 1996-2000 averages in the east. Green-winged teal
(P=0.03) and ring-necked ducks (P=0.002) were below their 1996-2000 averages, and all
other species were similar to their long-term averages (P>0.14).
Habitat conditions in the traditional survey area were variable. The estimate of
May ponds (U. S. and Prairie Canada combined) is up 18% (4.6 ± 0.1 million, P=0.001)
compared to 2000, but not statistically different from the long-term average (-6%,
P=0.07). Continued drought produced fair to poor conditions in most of Alberta, central
and southern Saskatchewan, and eastern Montana. By contrast, North and South Dakota
generally had good to excellent water conditions, with the best conditions in the eastern
portions of these states, and drier conditions to the north and west. Nesting cover in the
Dakotas was in above-average condition. Southern Manitoba and extreme southeastern
Saskatchewan have had higher than normal water conditions for the past two years, and
this water, along with above normal precipitation due to an early, snowy winter, produced
excellent habitat for breeding ducks. Average to above-average precipitation also made
for excellent wetland conditions across northern Manitoba and Saskatchewan. The
northernmost portion of Alberta was the exception to the record drought and poor
wetland conditions in the rest of the province, as above-average winter and spring
precipitation filled nearly all available wetland basins. Good conditions for breeding
ducks prevailed in the Northwest Territories, except for a small northern area that was
rated only fair due to late spring ice conditions that reduced available breeding habitat for
early-nesting species. In Alaska, breeding conditions depend largely on the timing of
spring, as wetland conditions are less variable than on the prairies. Although winter
temperatures were mild, spring was late, and waterfowl production will likely be below
average to the north and west, and average to the south and east. Overall, conditions
were good in the traditional survey area, and average to above-average waterfowl
production is expected.
In the eastern survey area, conditions were variable but generally good. Southern
Ontario and northern New York enjoyed an early spring, and with wetland basins nearly
full, the outlook for breeding ducks is good. Spring was also early in Quebec, with good
to excellent habitat in the central and northern portions. However, southern Quebec was
drier, and conditions there ranged from fair to poor. In Maine and the Maritime
provinces spring was late, with lower than normal temperatures, but above-average
precipitation, and habitat conditions were rated good throughout the region. Overall,
eastern habitats were in good condition, with average to above-average waterfowl
production expected.
2
The data in this report were contributed by the following individuals:
Alaska and Yukon Territory (Old Crow Flats): B. Conant and D. Groves
Northern Alberta, Northeastern British Columbia, and Northwest Territories: C. Ferguson and P. Corr
Northern Saskatchewan and Northern Manitoba: F. Roetker and J. Kreilich, Jr.
Southern and Central Alberta:
Air E. Buelna and A. Davenport
Ground D. Duncan a, P. Pryor a, K. Froggatt b, S. Barry a, E. Hofman b, R. Russell b, B. Peers c, T.
Matthews c, M. Johnson a, L. Crowe a, C. Procter a, J. Spenst b, S. Witham c, M. Barr c
Southern Saskatchewan:
Air P. Thorpe, K. Bollinger, R. King, and H. Bell
Ground D. Nieman a, J. Smith a, K. Warner a, C. Downie a, M. Hosegood a, C. Lévesque a, P.
Nieman a, C. Park a, A. Williams a, D. Caswell a, M. Schuster a, P. Rakowski a, D. Pisiak b,
M. Van Osch c, M. Blanchard a, J. Galbraith a, F. Baldwin, Jr. a, A. Dupuis a, B. Carles b
Southern Manitoba:
Air R. King, and H. Bell
Ground D. Caswell a, M. Schuster a, P. Rakowski a, D. Pisiak b, M. Van Osch c, G. Ball b, M.
Blanchard a, J. Galbraith a, F. Baldwin, Jr. a, A. Dupuis a, G. Hochbaum a, B. Carles b
Montana and Western Dakotas
Air J. Voelzer and R. Bentley
Ground A. Arnold d and V. Griego
Central and Eastern Dakotas
Air J. W. Solberg and S. Thomas
Ground G. T. Allen, M. Ellingson, P. R. Garrettson, D. M. Prellwitz
Northern Quebec: J. Wortham and M. Francke
New York, Eastern Ontario, and Southern Quebec: M. Koneff, C. Kitchens-Hayes, D. Holtby b, M. Miller b
Central and Western Ontario: W. Butler, B. Fisher, D. Holtby b, J. Drahota, B. Raftovich
Maine and Maritimes: J. Bidwell and M. Drut
a Canadian Wildlife Service
b State, Provincial, or Tribal Conservation Agency
c Ducks Unlimited - Canada
d Other organization
All others – U.S. Fish and Wildlife Service
3
Table 1. Estimated number (in thousands) of May ponds in portions of Prairie Canada and the northcentral U.S.
Change from 2000 Change from LTA
Survey Area 2000 2001 % P LTAa % P
Prairie Canada
S. Alberta 553 426 -23 0.032 736 -42 <0.001
S. Saskatchewan 1404 1536 +9 0.277 2004 -23 <0.001
S. Manitoba 466 786 +69 <0.001 685 +15 0.089
Subtotal 2422 2747 +13 0.031 3425 -20 <0.001
Northcentral U.S.
Montana and Western Dakotas 429 346 -19 0.040 536 -35 <0.001
Eastern Dakotas 1095 1548 +41 <0.001 982 +58 <0.001
Subtotal 1524 1893 +24 0.006 1518 +25 <0.001
Grand Total 3947 4640 +18 0.001 4916 -6 0.071
aLong-term average. Prairie Canada, 1961-2000; northcentral U.S. and Grand Total, 1974-2000.
Millions
Prairie Canada
Northcentral U.S.
Total
0
1
2
3
4
5
6
7
8
9
10
Year
1960 1966 1972 1978 1984 1990 1996 2002
Figure 1. Number of ponds in May and 95% confidence intervals for Prairie Canada and the Northcentral U.S.
4
Table 2. Duck breeding population estimates a (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
6727 6427 -4 0.449 3335 +93 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
6900 5489 -20 <0.001 7297 -25 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario
3468 2656 -23 0.014 3552 -25 <0.001
S. Alberta 3485 2521 -28 <0.001 4460 -43 <0.001
S. Saskatchewan 7665 6442 -16 0.001 7429 -13 <0.001
S. Manitoba 1486 1793 +21 0.016 1543 +16 0.007
Montana and Western Dakotas 1726 1588 -8 0.271 1625 -2 0.692
Eastern Dakotas 10382 9261 -11 0.049 3983 +133 <0.001
Total 41838 36177 -14 <0.001 33224 +9 <0.001
a Includes black duck, ring-necked duck, goldeneye, bufflehead, and ruddy duck; excludes eider, long-tailed duck, wood duck, scoter, merganser, and wood duck.
Table 3. Mallard breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
770 718 -7 0.489 315 +128 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
1288 979 -24 0.029 1110 -12 0.103
N. Saskatchewan- N. Manitoba
- W. Ontario
1049 603 -42 0.001 1175 -49 <0.001
S. Alberta 833 744 -11 0.386 1143 -35 <0.001
S. Saskatchewan 2267 1650 -27 <0.001 2117 -22 <0.001
S. Manitoba 368 446 +21 0.141 371 +20 0.090
Montana and Western Dakotas 622 463 -26 0.035 504 -8 0.381
Eastern Dakotas 2273 2301 +1 0.897 759 +203 <0.001
Total 9470 7904 -17 <0.001 7494 +5 0.078
5
Table 4. Gadwall breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
3 7 +140 0.360 2 +281 0.199
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
100 111 +12 0.672 40 +179 0.001
N. Saskatchewan- N. Manitoba
- W. Ontario
12 15 +25 0.696 28 -47 0.034
S. Alberta 311 257 -17 0.320 311 -17 0.041
S. Saskatchewan 650 715 +10 0.541 538 +33 0.045
S. Manitoba 85 106 +25 0.141 61 +75 <0.001
Montana and Western Dakotas 289 403 +39 0.084 189 +113 <0.001
Eastern Dakotas 1709 1066 -38 0.001 443 +141 <0.001
Total 3158 2679 -15 0.048 1610 +66 <0.001
Table 5. American wigeon breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
1141 1106 -3 0.769 459 +141 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
722 728 +1 0.963 937 -22 0.055
N. Saskatchewan- N. Manitoba
- W. Ontario
147 100 -32 0.174 262 -62 <0.001
S. Alberta 225 187 -17 0.593 315 -41 0.002
S. Saskatchewan 253 177 -30 0.031 450 -61 <0.001
S. Manitoba 19 18 -6 0.768 66 -73 <0.001
Montana and Western Dakotas 122 88 -28 0.252 114 -23 0.257
Eastern Dakotas 104 90 -13 0.632 45 +100 0.010
Total 2733 2494 -9 0.240 2649 -6 0.307
6
Table 6. Green-winged teal breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
946 1029 +9 0.490 305 +238 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
1282 742 -42 0.005 753 -2 0.911
N. Saskatchewan- N. Manitoba
- W. Ontario
189 181 -4 0.856 186 -2 0.870
S. Alberta 308 190 -38 0.164 199 -4 0.846
S. Saskatchewan 295 202 -31 0.061 231 -12 0.394
S. Manitoba 61 31 -48 0.026 53 -41 0.003
Montana and Western Dakotas 60 64 +6 0.890 35 +81 0.109
Eastern Dakotas 52 69 +32 0.465 44 +56 0.205
Total 3194 2509 -21 0.007 1806 +39 <0.001
Table 7. Blue-winged teal breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
0 0 - - 1 -100 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
275 119 -57 0.011 270 -56 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario
126 148 +18 0.565 276 -46 <0.001
S. Alberta 578 368 -36 0.045 632 -42 <0.001
S. Saskatchewan 1622 1267 -22 0.081 1207 +5 0.639
S. Manitoba 355 484 +36 0.097 385 +26 0.050
Montana and Western Dakotas 238 158 -34 0.055 261 -40 <0.001
Eastern Dakotas 4238 3212 -24 0.021 1433 +124 <0.001
Total 7431 5757 -23 0.001 4465 +29 <0.001
7
Table 8. Northern shoveler breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
846 666 -21 0.152 225 +196 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
248 204 -18 0.482 207 -2 0.934
N. Saskatchewan- N. Manitoba
- W. Ontario
36 28 -23 0.547 45 -38 0.027
S. Alberta 380 268 -30 0.208 357 -25 0.161
S. Saskatchewan 900 718 -20 0.182 619 +16 0.275
S. Manitoba 176 199 +13 0.542 102 +95 0.001
Montana and Western Dakotas 161 152 -5 0.799 146 +4 0.819
Eastern Dakotas 774 1079 +39 0.022 371 +191 <0.001
Total 3521 3314 -6 0.423 2073 +60 <0.001
Table 9. Northern pintail breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
1452 1426 -2 0.924 902 +58 0.020
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
220 175 -21 0.255 401 -56 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario
16 10 -38 0.296 44 -78 <0.001
S. Alberta 189 66 -65 <0.001 782 -92 <0.001
S. Saskatchewan 464 680 +47 0.070 1281 -47 <0.001
S. Manitoba 45 97 +117 0.014 118 -18 0.267
Montana and Western Dakotas 169 161 -5 0.787 285 -43 <0.001
Eastern Dakotas 353 680 +93 0.001 474 +43 0.017
Total 2908 3296 +13 0.220 4289 -23 <0.001
8
Table 10. Redhead breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
1 0 -100 0.345 1 -100 <0.001
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
26 26 +2 0.955 38 -30 0.119
N. Saskatchewan- N. Manitoba
- W. Ontario
41 8 -80 0.069 29 -72 <0.001
S. Alberta 107 54 -49 0.104 120 -55 <0.001
S. Saskatchewan 324 224 -31 0.064 190 +18 0.294
S. Manitoba 88 117 +34 0.557 70 +67 0.198
Montana and Western Dakotas 10 13 +30 0.711 9 +46 0.485
Eastern Dakotas 331 269 -19 0.336 168 +60 0.035
Total 926 712 -23 0.041 624 +14 0.218
Table 11. Canvasback breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
187 89 -52 0.182 89 0 0.997
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
83 63 -25 0.345 70 -10 0.621
N. Saskatchewan- N. Manitoba
- W. Ontario
37 32 -14 0.744 58 -45 0.018
S. Alberta 73 32 -56 0.054 66 -52 0.024
S. Saskatchewan 232 232 0 1.000 185 +25 0.210
S. Manitoba 64 56 -12 0.673 56 +1 0.968
Montana and Western Dakotas 7 6 -15 0.800 8 -24 0.368
Eastern Dakotas 24 70 +191 0.008 32 +120 0.019
Total 707 580 -18 0.189 563 +3 0.756
9
Table 12. Scaup (greater and lesser) breeding population estimates (in thousands) for regions in the traditional survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTA % P
Alaska-Yukon Territory
– Old Crow Flats
1219 1148 -6 0.661 909 +26 0.034
C. & N. Alberta – N.E. British Columbia
- Northwest Territories
1621 1476 -9 0.447 2739 -46 <0.001
N. Saskatchewan- N. Manitoba
- W. Ontario
293 267 -9 0.785 609 -56 <0.001
S. Alberta 292 202 -31 0.234 375 -46 0.004
S. Saskatchewan 273 321 +18 0.567 434 -26 0.108
S. Manitoba 60 74 +23 0.635 144 -49 0.010
Montana and Western Dakotas 41 42 +3 0.928 56 -24 0.197
Eastern Dakotas 227 164 -28 0.233 88 +85 0.039
Total 4026 3694 -8 0.264 5353 -31 <0.001
10
Table 13. Duck breeding population estimatesa (in thousands, for the 10 most abundant species) for the eastern survey area.
Change from 2000 Change from LTA
Region 2000 2001 % P LTAb % P
Mergansers 400 429 +7 0.729 496 -14 0.435
Mallard 212 286 +35 0.153 306 -7 0.661
American Black Duck 397 422 +6 0.730 485 -13 0.271
American Wigeon 42 77 +86 0.192 61 +28 0.442
Green-winged teal 202 220 +9 0.671 314 -30 0.032
Lesser Scaup 116 204 +75 0.371 41 +392 0.080
Ring-necked duck 619 353 -43 0.001 533 -34 0.002
Goldeneye (common & Barrow’s) 947 1032 +9 0.820 643 +61 0.075
Bufflehead 49 95 +93 0.054 47 +100 0.029
Scoters 182 179 -2 0.963 100 +78 0.137
Total 3204 3337 +4 0.757 3075 +9 0.351
a Includes gadwall, northern shoveler, northern pintail, and scaup. Excludes eider, long-tailed duck, wood duck, redhead, canvasback, and ruddy duck.
bLong-term average from 1996.
11
3
1 2
4
5 6
8
9
10 11
12
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15
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75
76
77
36
37
39 38
40
41
42 43
44
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46
47
48
49
50 51
52
53
54 55
56
25
18
7
20
62
63
64
65
68
69
66
67
Figure 2. Transects and strata for areas of the Breeding Waterfowl and Habitat Survey.
12
Moderate to severe dryness
Near normal
Moderate to extreme wetness
2000 2001
Figure 3. Palmer long-term drought indices for the contiguous U.S. and provinces of Canada for which data were available. U.S. PDI map from Weekly Weather and Crop Bulletin May 31, 2000 and May 30,
2001; Canadian PDI map from Environment Canada May 2000 and May 2001.
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Poor
Fair
Good
Excellent
  
  
  
  
Figure 4. Preliminary breeding waterfowl habitat conditions during May 2001, as judged by U.S. Fish & Wildlife Service Flyway Biologists.
14
Appendix A. Breeding population estimates and standard errors (in thousands) for 10 species of ducks from the
traditional survey area (strata 1-18, 20-50, 75-77).
Mallard Gadwall American wigeon Green-winged teal Blue-winged teal
Year Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
SˆE
1955 8777.3 457.1 651.5 149.5 3216.8 297.8 1807.2 291.5 5305.2 567.6
1956 10452.7 461.8 772.6 142.4 3145.0 227.8 1525.3 236.2 4997.6 527.6
1957 9296.9 443.5 666.8 148.2 2919.8 291.5 1102.9 161.2 4299.5 467.3
1958 11234.2 555.6 502.0 89.6 2551.7 177.9 1347.4 212.2 5456.6 483.7
1959 9024.3 466.6 590.0 72.7 3787.7 339.2 2653.4 459.3 5099.3 332.7
1960 7371.7 354.1 784.1 68.4 2987.6 407.0 1426.9 311.0 4293.0 294.3
1961 7330.0 510.5 654.8 77.5 3048.3 319.9 1729.3 251.5 3655.3 298.7
1962 5535.9 426.9 905.1 87.0 1958.7 145.4 722.9 117.6 3011.1 209.8
1963 6748.8 326.8 1055.3 89.5 1830.8 169.9 1242.3 226.9 3723.6 323.0
1964 6063.9 385.3 873.4 73.7 2589.6 259.7 1561.3 244.7 4020.6 320.4
1965 5131.7 274.8 1260.3 114.8 2301.1 189.4 1282.0 151.0 3594.5 270.4
1966 6731.9 311.4 1680.4 132.4 2318.4 139.2 1617.3 173.6 3733.2 233.6
1967 7509.5 338.2 1384.6 97.8 2325.5 136.2 1593.7 165.7 4491.5 305.7
1968 7089.2 340.8 1949.0 213.9 2298.6 156.1 1430.9 146.6 3462.5 389.1
1969 7531.6 280.2 1573.4 100.2 2941.4 168.6 1491.0 103.5 4138.6 239.5
1970 9985.9 617.2 1608.1 123.5 3469.9 318.5 2182.5 137.7 4861.8 372.3
1971 9416.4 459.5 1605.6 123.0 3272.9 186.2 1889.3 132.9 4610.2 322.8
1972 9265.5 363.9 1622.9 120.1 3200.1 194.1 1948.2 185.8 4278.5 230.5
1973 8079.2 377.5 1245.6 90.3 2877.9 197.4 1949.2 131.9 3332.5 220.3
1974 6880.2 351.8 1592.4 128.2 2672.0 159.3 1864.5 131.2 4976.2 394.6
1975 7726.9 344.1 1643.9 109.0 2778.3 192.0 1664.8 148.1 5885.4 337.4
1976 7933.6 337.4 1244.8 85.7 2505.2 152.7 1547.5 134.0 4744.7 294.5
1977 7397.1 381.8 1299.0 126.4 2575.1 185.9 1285.8 87.9 4462.8 328.4
1978 7425.0 307.0 1558.0 92.2 3282.4 208.0 2174.2 219.1 4498.6 293.3
1979 7883.4 327.0 1757.9 121.0 3106.5 198.2 2071.7 198.5 4875.9 297.6
1980 7706.5 307.2 1392.9 98.8 3595.5 213.2 2049.9 140.7 4895.1 295.6
1981 6409.7 308.4 1395.4 120.0 2946.0 173.0 1910.5 141.7 3720.6 242.1
1982 6408.5 302.2 1633.8 126.2 2458.7 167.3 1535.7 140.2 3657.6 203.7
1983 6456.0 286.9 1519.2 144.3 2636.2 181.4 1875.0 148.0 3366.5 197.2
1984 5415.3 258.4 1515.0 125.0 3002.2 174.2 1408.2 91.5 3979.3 267.6
1985 4960.9 234.7 1303.0 98.2 2050.7 143.7 1475.4 100.3 3502.4 246.3
1986 6124.2 241.6 1547.1 107.5 1736.5 109.9 1674.9 136.1 4478.8 237.1
1987 5789.8 217.9 1305.6 97.1 2012.5 134.3 2006.2 180.4 3528.7 220.2
1988 6369.3 310.3 1349.9 121.1 2211.1 139.1 2060.8 188.3 4011.1 290.4
1989 5645.4 244.1 1414.6 106.6 1972.9 106.0 1841.7 166.4 3125.3 229.8
1990 5452.4 238.6 1672.1 135.8 1860.1 108.3 1789.5 172.7 2776.4 178.7
1991 5444.6 205.6 1583.7 111.8 2254.0 139.5 1557.8 111.3 3763.7 270.8
1992 5976.1 241.0 2032.8 143.4 2208.4 131.9 1773.1 123.7 4333.1 263.2
1993 5708.3 208.9 1755.2 107.9 2053.0 109.3 1694.5 112.7 3192.9 205.6
1994 6980.1 282.8 2318.3 145.2 2382.2 130.3 2108.4 152.2 4616.2 259.2
1995 8269.4 287.5 2835.7 187.5 2614.5 136.3 2300.6 140.3 5140.0 253.3
1996 7941.3 262.9 2984.0 152.5 2271.7 125.4 2499.5 153.4 6407.4 353.9
1997 9939.7 308.5 3897.2 264.9 3117.6 161.6 2506.6 142.5 6124.3 330.7
1998 9640.4 301.6 3742.2 205.6 2857.7 145.3 2087.3 138.9 6398.8 332.3
1999 10805.7 344.5 3235.5 163.8 2920.1 185.5 2631.0 174.6 7149.5 364.5
2000 9470.2 290.2 3158.4 200.7 2733.1 138.8 3193.5 200.1 7431.4 425.0
2001 7904.0 226.9 2679.2 136.1 2493.5 149.6 2508.7 156.4 5757.0 288.8
17
Appendix A. Continued.
Northern shoveler Northern pintail Redhead Canvasback Scaup
Year Nˆ
E Sˆ Nˆ
Nˆ
Nˆ
E Sˆ E Sˆ E Sˆ Nˆ
SˆE
1955 1642.8 218.7 9775.1 656.1 539.9 98.9 589.3 87.8 5620.1 582.1
1956 1781.4 196.4 10372.8 694.4 757.3 119.3 698.5 93.3 5994.1 434.0
1957 1476.1 181.8 6606.9 493.4 509.1 95.7 626.1 94.7 5766.9 411.7
1958 1383.8 185.1 6037.9 447.9 457.1 66.2 746.8 96.1 5350.4 355.1
1959 1577.6 301.1 5872.7 371.6 498.8 55.5 488.7 50.6 7037.6 492.3
1960 1824.5 130.1 5722.2 323.2 497.8 67.0 605.7 82.4 4868.6 362.5
1961 1383.0 166.5 4218.2 496.2 323.3 38.8 435.3 65.7 5380.0 442.2
1962 1269.0 113.9 3623.5 243.1 507.5 60.0 360.2 43.8 5286.1 426.4
1963 1398.4 143.8 3846.0 255.6 413.4 61.9 506.2 74.9 5438.4 357.9
1964 1718.3 240.3 3291.2 239.4 528.1 67.3 643.6 126.9 5131.8 386.1
1965 1423.7 114.1 3591.9 221.9 599.3 77.7 522.1 52.8 4640.0 411.2
1966 2147.0 163.9 4811.9 265.6 713.1 77.6 663.1 78.0 4439.2 356.2
1967 2314.7 154.6 5277.7 341.9 735.7 79.0 502.6 45.4 4927.7 456.1
1968 1684.5 176.8 3489.4 244.6 499.4 53.6 563.7 101.3 4412.7 351.8
1969 2156.8 117.2 5903.9 296.2 633.2 53.6 503.5 53.7 5139.8 378.5
1970 2230.4 117.4 6392.0 396.7 622.3 64.3 580.1 90.4 5662.5 391.4
1971 2011.4 122.7 5847.2 368.1 534.4 57.0 450.7 55.2 5143.3 333.8
1972 2466.5 182.8 6979.0 364.5 550.9 49.4 425.9 46.0 7997.0 718.0
1973 1619.0 112.2 4356.2 267.0 500.8 57.7 620.5 89.1 6257.4 523.1
1974 2011.3 129.9 6598.2 345.8 626.3 70.8 512.8 56.8 5780.5 409.8
1975 1980.8 106.7 5900.4 267.3 831.9 93.5 595.1 56.1 6460.0 486.0
1976 1748.1 106.9 5475.6 299.2 665.9 66.3 614.4 70.1 5818.7 348.7
1977 1451.8 82.1 3926.1 246.8 634.0 79.9 664.0 74.9 6260.2 362.8
1978 1975.3 115.6 5108.2 267.8 724.6 62.2 373.2 41.5 5984.4 403.0
1979 2406.5 135.6 5376.1 274.4 697.5 63.8 582.0 59.8 7657.9 548.6
1980 1908.2 119.9 4508.1 228.6 728.4 116.7 734.6 83.8 6381.7 421.2
1981 2333.6 177.4 3479.5 260.5 594.9 62.0 620.8 59.1 5990.9 414.2
1982 2147.6 121.7 3708.8 226.6 616.9 74.2 513.3 50.9 5532.0 380.9
1983 1875.7 105.3 3510.6 178.1 711.9 83.3 526.6 58.9 7173.8 494.9
1984 1618.2 91.9 2964.8 166.8 671.3 72.0 530.1 60.1 7024.3 484.7
1985 1702.1 125.7 2515.5 143.0 578.2 67.1 375.9 42.9 5098.0 333.1
1986 2128.2 112.0 2739.7 152.1 559.6 60.5 438.3 41.5 5235.3 355.5
1987 1950.2 118.4 2628.3 159.4 502.4 54.9 450.1 77.9 4862.7 303.8
1988 1680.9 210.4 2005.5 164.0 441.9 66.2 435.0 40.2 4671.4 309.5
1989 1538.3 95.9 2111.9 181.3 510.7 58.5 477.4 48.4 4342.1 291.3
1990 1759.3 118.6 2256.6 183.3 480.9 48.2 539.3 60.3 4293.1 264.9
1991 1716.2 104.6 1803.4 131.3 445.6 42.1 491.2 66.4 5254.9 364.9
1992 1954.4 132.1 2098.1 161.0 595.6 69.7 481.5 97.3 4639.2 291.9
1993 2046.5 114.3 2053.4 124.2 485.4 53.1 472.1 67.6 4080.1 249.4
1994 2912.0 141.4 2972.3 188.0 653.5 66.7 525.6 71.1 4529.0 253.6
1995 2854.9 150.3 2757.9 177.6 888.5 90.6 770.6 92.2 4446.4 277.6
1996 3449.0 165.7 2735.9 147.5 834.2 83.1 848.5 118.3 4217.4 234.5
1997 4120.4 194.0 3558.0 194.2 918.3 77.2 688.8 57.2 4112.3 224.2
1998 3183.2 156.5 2520.6 136.8 1005.1 122.9 685.9 63.8 3471.9 191.2
1999 3889.5 202.1 3057.9 230.5 973.4 69.5 716.0 79.1 4411.7 227.9
2000 3520.7 197.9 2907.6 170.5 926.3 78.1 706.8 81.0 4026.3 205.3
2001 3313.5 166.8 3296.0 266.6 712.0 70.2 579.8 52.7 3694.0 214.9
18
Appendix B. Breeding population estimates and standard errors (in thousands) for the 10 most abundant species of ducks in the eastern survey area, 1990-2001 a.
Mergansers Mallards American
Black Duck
American
Wigeon
Am. Green-winged
teal
Lesser
Scaup
Ring-necked
duck
Goldeneye
spp.
Bufflehead Scoter spp.
Year Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
E ˆ S Nˆ
ˆ E S Nˆ
E ˆ S Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
E Sˆ Nˆ
SˆE
1990 157.5 48.3 208.6 47.7 160.9 33.5 31.0 22.6 47.1 8.6 135.7 56.2 92.1 28.3 73.3 22.2 99.9 22.9 1.9 1.9
1991 263.9 78.6 169.8 34.5 126.0 35.3 45.4 21.8 42.2 14.4 43.5 16.4 158.1 30.2 138.4 44.3 94.1 32.1 6.4 5.3
1992 128.1 24.3 362.2 54.1 160.3 33.1 15.4 9.3 43.8 13.9 65.6 23.2 251.6 62.3 241.0 55.2 59.0 13.7 3.0 2.3
1993 164.9 23.7 333.8 49.7 124.6 25.6 9.4 7.4 47.4 9.9 288.6 235.3 248.1 65.1 90.2 32.6 13.1 3.6 0.0 0.0
1994 358.4 91.8 238.6 28.8 116.3 20.7 18.9 9.6 169.2 24.0 81.9 31.7 163.5 62.6 55.0 17.4 33.4 14.0 18.3 9.7
1995 376.3 89.7 212.6 41.1 234.5 46.6 13.8 7.9 96.2 14.1 62.0 20.5 195.6 51.0 9.2 3.7 26.5 8.8 5.0 4.8
1996 1083.1 279.6 387.6 63.6 562.2 97.1 34.7 17.0 436.2 86.9 38.5 15.1 611.9 98.7 410.3 169.7 50.6 12.5 23.6 10.5
1997 379.1 53.0 287.6 44.8 434.5 63.1 22.5 11.2 211.5 31.3 16.7 7.2 617.6 151.1 220.6 54.8 22.3 6.7 88.9 50.2
1998 327.4 38.8 363.2 71.3 542.1 55.4 83.6 24.6 299.5 81.1 20.1 10.6 361.8 53.8 715.7 124.7 44.6 10.3 159.4 47.1
1999 290.0 39.4 280.8 39.2 488.7 51.3 121.1 45.6 422.4 62.3 44.9 20.5 453.2 76.0 920.0 167.3 70.5 20.8 47.0 17.7
2000 400.0 54.0 212.3 31.3 396.9 53.9 41.7 20.4 201.6 28.7 19.8 9.1 618.8 71.3 946.5 318.7 49.3 11.3 182.1 59.0
2001 428.7 62.8 285.7 40.8 422.0 48.8 77.5 18.2 220.3 33.5 203.5 92.2 352.8 39.6 1032.2 202.4 95.0 20.9 178.6 49.4
a Maine estimates were included beginning in 1995. Quebec estimates were included beginning in 1996. Therefore, estimates are only comparable within year groups 1990-94, and
1996-present.
19