Waterfowl: Population Status, 2005

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 2005-2006 hunting season

Waterfowl Population Status, 2002

In the traditional survey area (strata 1-18, 20-50, and 75-77), total duck abundance was 31.2 + 0.5 [SE] million birds. This was 14% below (P\u3c 0.001) last year’s estimate of 36.1 ± 0.6 million birds, and 6% below the long-term (1955-2001) average (P\u3c0.001). Mallard (Anas platyrhynchos) abundance was 7.5 ± 0.2 million, similar to (P=0.23) the 2001 estimate of 7.9 ± 0.2 million, and essentially identical to the long-term average (P=1.00). Blue-winged teal (A. discors) abundance was 4.2 ± 0.2 million, which was 27% below last year’s estimate of 5.8 ± 0.3 million (P\u3c0.001), but similar to the long-term average (P=0.22). Gadwall (A. strepera; 2.2 ± 0.1 million, -17%), shovelers (A. clypeata; 2.3 ± 0.1 million, -30%), and pintails (A. acuta; 1.8 ± 0.1 million, -46%) were below 2001 estimates (P\u3c0.02). Wigeon (A. americana; 2.3 ± 0.1 million), green-winged teal (A. crecca; 2.3 ± 0.1 million), redheads (Aythya americana; 0.6 ± 0.1 million), canvasbacks (Aythya valisineria; 0.5 ± 0.1 million), and scaup (Aythya marila and A. affinis combined; 3.5 ± 0.2 million) were unchanged from 2001 estimates. Gadwall (+37%), green-winged teal (+28%), and shovelers (+10%) all remained above their long-term averages, whereas wigeon (-12%), pintail (-58%), canvasback (-14%), and scaup numbers (-34%) were below long-term averages. Northern pintails and scaup were the lowest and second lowest counts on record, respectively. The redhead estimate was similar to the long-term average. Below-average winter and spring precipitation in the prairies and parklands were reflected in pond counts much lower than in 2001. Total May ponds (U.S. prairies and prairie and parkland Canada combined) of 2.7 ± 0.1 million were the second lowest since 1974, when this estimate was first recorded, 41% below last year’s estimate of 4.6 ± 0.1 million (P\u3c0.001), and 45% below (P\u3c0.001) the long-term average. The projected mid-continent mallard fall flight index is 8.9 million, statistically similar to last year\u27s. The eastern survey area is comprised of strata 51-56 and 62-69. The 2002 total duck population estimate for this area was 4.4 ± 0.3 million birds, 32% higher than last year\u27s (3.3 ± 0.3 million, P=0.01), and 41% higher than the 1996-2001 average (P\u3c0.001). Numbers of most individual species were similar to those of last year, with the exception of mergansers (Lophodytes cucullatus and Mergus spp.; 0.8 ± 0.1 million, +90%, P\u3c0.001) and green-winged teal (0.7 ± 0.1 million, +174%, P=0.01), which increased compared to last year. Mergansers (+68%) and green-winged teal (+102%) were also above their 1996-2001 averages, as were scoters (Melanitta spp.; 0.3 ± 0.1 million, +178%, P=0.01). Estimates for all other species were similar to last year\u27s estimates and to long-term averages

Waterfowl Population Status, 2002

In the traditional survey area (strata 1-18, 20-50, and 75-77), total duck abundance was 31.2 + 0.5 [SE] million birds. This was 14% below (P\u3c 0.001) last year’s estimate of 36.1 ± 0.6 million birds, and 6% below the long-term (1955-2001) average (P\u3c0.001). Mallard (Anas platyrhynchos) abundance was 7.5 ± 0.2 million, similar to (P=0.23) the 2001 estimate of 7.9 ± 0.2 million, and essentially identical to the long-term average (P=1.00). Blue-winged teal (A. discors) abundance was 4.2 ± 0.2 million, which was 27% below last year’s estimate of 5.8 ± 0.3 million (P\u3c0.001), but similar to the long-term average (P=0.22). Gadwall (A. strepera; 2.2 ± 0.1 million, -17%), shovelers (A. clypeata; 2.3 ± 0.1 million, -30%), and pintails (A. acuta; 1.8 ± 0.1 million, -46%) were below 2001 estimates (P\u3c0.02). Wigeon (A. americana; 2.3 ± 0.1 million), green-winged teal (A. crecca; 2.3 ± 0.1 million), redheads (Aythya americana; 0.6 ± 0.1 million), canvasbacks (Aythya valisineria; 0.5 ± 0.1 million), and scaup (Aythya marila and A. affinis combined; 3.5 ± 0.2 million) were unchanged from 2001 estimates. Gadwall (+37%), green-winged teal (+28%), and shovelers (+10%) all remained above their long-term averages, whereas wigeon (-12%), pintail (-58%), canvasback (-14%), and scaup numbers (-34%) were below long-term averages. Northern pintails and scaup were the lowest and second lowest counts on record, respectively. The redhead estimate was similar to the long-term average. Below-average winter and spring precipitation in the prairies and parklands were reflected in pond counts much lower than in 2001. Total May ponds (U.S. prairies and prairie and parkland Canada combined) of 2.7 ± 0.1 million were the second lowest since 1974, when this estimate was first recorded, 41% below last year’s estimate of 4.6 ± 0.1 million (P\u3c0.001), and 45% below (P\u3c0.001) the long-term average. The projected mid-continent mallard fall flight index is 8.9 million, statistically similar to last year\u27s. The eastern survey area is comprised of strata 51-56 and 62-69. The 2002 total duck population estimate for this area was 4.4 ± 0.3 million birds, 32% higher than last year\u27s (3.3 ± 0.3 million, P=0.01), and 41% higher than the 1996-2001 average (P\u3c0.001). Numbers of most individual species were similar to those of last year, with the exception of mergansers (Lophodytes cucullatus and Mergus spp.; 0.8 ± 0.1 million, +90%, P\u3c0.001) and green-winged teal (0.7 ± 0.1 million, +174%, P=0.01), which increased compared to last year. Mergansers (+68%) and green-winged teal (+102%) were also above their 1996-2001 averages, as were scoters (Melanitta spp.; 0.3 ± 0.1 million, +178%, P=0.01). Estimates for all other species were similar to last year\u27s estimates and to long-term averages

Waterfowl: Population Status, 2005

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 2005-2006 hunting season

CAN PREDATOR TRAPPING IMPROVE WATERFOWL RECRUITMENT IN THE PRAIRIE POTHOLE REGION?

We contrasted nest success for control areas and experimental areas in eastern North Dakota where we employed professionals to trap mammalian nest predators from late March to late July. In 1995, dabbling ducks averaged 53% nest success on four treatment blocks of 4,150 ha each; whereas on four control areas upland nesting ducks averaged 24% success. Diving duck nest success averaged 57% on experimental areas and 29% on control areas. American coot (Fulica americana) nest success also improved on experimental areas, but blackbird nesting and fledging success were not affected by the treatment. In 1994, nest success of upland cresting ducks was 52%, which was a striking contrast with upland nest success of 6% on the control area. In 1994 and 1995, brood counts were much higher on the experimental areas than on the control areas. Track counts revealed lower estimates of predator activity on experimental sites compared to control sites. This study provides the first strong experimental documentation that trapping, without the use of poisons, can effectively reduce nest predation and substantially improve waterfowl recruitment

Waterfowl Population Status, 2006

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), Ringnecked 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

Waterfowl Population Status, 2001

In the traditional survey area (strata 1-18, 20-50, and 75-77), total duck abundance was 36.1 ± 0.6 [SE] million birds. This was 14% below (P\u3c 0.001) last year’s estimate of 41.8 ± 0.7 million birds, but still 9% above the long-term (1955-2000) average (P \u3c 0.001). Mallard (Anas platyrhynchos) abundance was 7.9 ± 0.2 million, which is 17% below (P\u3c0.001) the 2000 estimate of 9.5 ± 0.3 million and similar to the long-term average (P=0.08). Blue-winged teal (Anas discors) abundance was 5.8 ± 0.3 million, which was 23% below last year’s estimate of 7.4 ± 0.4 million (P=0.001), but 29% above the long-term average (P = 0.001). Green-winged teal (Anas crecca) abundance was 2.5 ± 0.2 million, 39% above the long-term average (P\u3c0.001) but 21% lower than last year (P=0.007). Gadwall (Anas strepera; 2.7 ± 0.1 million, +66%) and northern shovelers (Anas clypeata; 3.3 ± 0.2 million, +60%), were above their long-term averages (P \u3c 0.04), while northern pintails (Anas acuta; 3.3 ± 0.3 million, -23%) and scaup (Aythya marila and A. affinis combined; 3.7 ± 0.2 million, -31%) remained below their long-term averages (P\u3c0.01). Redheads (Aythya americana; 0.7 + 0.07 million) were 23% below 2000 numbers (P=0.04), and similar to their long-term average (P=0.22). American wigeon (Anas Americana; 2.5 + 0.1 million) and canvasback (Aythya valisineria; 0.6 + 0.05 million) estimates were similar to those of last year (P≥0.19) and to long-term averages (P≥0.22). Habitat conditions in May in the traditional survey area were generally wetter than last year, but varied considerably among areas. The estimate of May ponds in Prairie Canada and the U.S. combined was 4.6 ± 0.1 million, up 18% from 2000, but not statistically different from the long-term average (P=0.07). The eastern survey area comprises strata 51-56 and 62-69. The 2001 total duck population estimate for the eastern survey area was 3.3 ± 0.3 million birds, similar to last year’s total duck estimate of 3.2 ± 0.3 million birds. Abundances of individual species were similar to last year, with the exception of ring-necked ducks (Aythya collaris; 0.35 + 0.04 million, -43%, P=0.001) and buffleheads (Bucephala albeola; 0.10 ± 0.02 million, +93%, P = 0.05). The mid-continent mallard fall flight is predicted to be 10.5 million mallards, 6% lower than that of last year (P=0.02)

Waterfowl Population Status, 2004

In the Breeding Population and Habitat Survey traditional survey area (strata 1-18, 20-50, and 75-77), the total-duck population estimate was 32.2 ± 0.6 (± 1 standard error) million birds, 11% below last year’s estimate of 36.2 ± 0.7 million birds (P\u3c0.001), and 3% below the 1955-2003 long-term average (P=0.053). Mallards (Anas platyrhynchos) numbered 7.4 ± 0.3 million, similar to last year’s estimate of 7.9 ± 0.3 million birds (P=0.177) and to the long-term average (P=0.762). Blue-winged teal (A. discors) numbered 4.1 ± 0.2 million, 26% below last year’s estimate of 5.5 ± 0.3 million (P\u3c0.001) and 10% below the long-term average (P=0.073). Among other duck species, only northern shovelers (A. clypeata, 2.8 ± 0.2 million) and American wigeon (A. americana, 2.0 ± 0.1 million) differed significantly from (both 22% below, P\u3c0.003) their 2003 estimates. As in 2003, gadwall (A. strepera, 2.6 ± 0.2 million, +56%), green-winged teal (A. crecca, 2.5 ± 0.1 million, +33%), and northern shovelers (+32%) were above their long-term averages. Northern pintails (A. acuta, 2.2 ± 0.2 million, -48%), scaup (Aythya affinis and A. marila, 3.8 ± 0.2 million, -27%), and American wigeon (-25%) were well below their long-term averages in 2004 (P\u3c0.001). Total May ponds (Prairie Canada, and the north-central U.S. combined) were estimated at 3.9 ± 0.2 million, which is 24% lower than last year (P\u3c0.001) and 19% below the long-term average (P\u3c0.001). Pond numbers in both Canada (2.5 ± 0.1 million) and the U. S. (1.4 ± 0.1 million) were below 2003 estimates (-29% in Canada, and -16% in the U.S.; P\u3c0.033), and pond numbers in Canada were 25% below the long-term average for this region (P\u3c0.001). The projected mallard fall flight index was 9.4 ± 0.1 million birds, similar to the 2003 estimate of 10.3 ± 0.1 million (P=0.467). The eastern survey area is comprised of strata 51-56 and 62-69. The 2004 total-duck population estimate for this area was 3.9 ± 0.3 million birds. This estimate was similar to last year’s estimate of 3.6 ± 0.3 million birds, and to the 1996- 2003 average (P\u3e0.102). Individual species estimates for this area were similar to 2003 estimates and to 1996-2003 averages, with the exception of American wigeon (0.1 ± 0.1 million) and goldeneyes (Bucephala clangula and B. islandica, 0.4 ± 0.1 million) which were 61% and 42% below their 1996-2003 averages (P\u3c0.052), respectively, and ring-necked ducks (Aythya collaris, 0.7 ± 0.2 million), which increased 67% relative to their 2003 estimate (P=0.095)

Waterfowl Population Status, 2007

Table of Contents ACKNOWLEDGMENTS.............................................................................. 2 Status of Ducks METHODS ....................................................................................... 5 RESULTS AND DISCUSSION..................................................7 REFERENCES.......................................................... 30 Status of Geese and Swans METHODS ........................................................................................ 32 RESULTS AND DISCUSSION.............................................................. 34 Appendices Appendix A. Individuals who supplied information on the status of ducks ....................................... 48 Appendix B. Individuals who supplied information on the status of geese and swans..................... 50 Appendix C. Strata and transects of the Waterfowl Breeding Population and Habitat Survey......... 52 Appendix D. Estimated number of May ponds and standard errors in portions of Prairie and Parkland Canada and the northcentral U.S. ......................................................................... 53 Appendix E. Breeding population estimates for total ducks and mallards for states, provinces, or regions that conduct spring surveys ................................................................................. 54 Appendix F. Breeding population estimates and standard errors for 10 species of ducks from the traditional survey area ............................................................................................ 56 Appendix G. Total breeding duck estimates for the traditional survey area, in thousands............................................................................................................................. 58 Appendix H. Breeding population estimates and 90% confidence intervals or credibility intervals For the 10 most abundant species of ducks in the eastern survey area……………………..59 Appendix I. Abundance indices for North American Canada goose populations, 1969-2007.......... 60 Appendix J. Abundance indices for light goose, greater white-fronted goose, brant, emperor goose, and tundra swan populations during 1969-2007......................... 61 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.............................................................................. 18 Table 5. American wigeon breeding population estimates ............................................................... 18 Table 6. Green-winged teal breeding population estimates ............................................................. 19 Table 7. Blue-winged teal breeding population estimates ................................................................ 19 Table 8. Northern shoveler breeding population estimates .............................................................. 20 Table 9. Northern pintail breeding population estimates .................................................................. 20 Table 10. Redhead breeding population estimates .......................................................................... 21 Table 11. Canvasback breeding population estimates ..................................................................... 21 Table 12. Scaup (greater and lesser combined) breeding population estimates ............................. 22 Table 13. Duck breeding population estimates for the 10 most abundant species in the eastern survey area .................................................................... 22 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 ......................................................................................... 15 Figure 3. Breeding population estimates and 90% credibility intervals for selected species in the eastern survey area ...................................................................................................... 28 Figure 4. Breeding population estimates and 90% confidence intervals for selected species in the eastern survey area ...................................................................................................... 29 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 ............................. 33 Figure 2. Snow and ice cover in North America for spring ............................................................... 34 Figure 3. Approximate ranges of Canada goose populations in North America............................... 35 Figures 4-18. Indices to Canada goose populations’ status ............................................................ 34-41 Figure 19. Approximate ranges of selected goose populations in North America............................ 42 Figures 20-27. Indices to selected goose populations’ status ......................................................... 43-47 Figure 28. Approximate range of Emperor goose and tundra swan populations in North America ....................................................................................................................... 47 Figure 29. Indices to tundra swan populations’ status...................................................................... 4

Waterfowl Population Status, 2012

In the traditional survey area, which includes strata 1‒18, 20‒50, and 75‒77, the total duck population estimate was 48.6 ± 0.8 [SE] million birds. This estimate represents a 7% increase over last year\u27s estimate of 45.6 ± 0.8 million birds and was 43% above the long-term average (1955‒2011). Estimated mallard (Anas platyrhynchos) abundance was 10.6 ± 0.3 million birds, which was 15% above the 2011 estimate of 9.2 ± 0.3 million birds and 40% above the longterm average. Estimated abundance of gadwall (A. strepera; 3.6 ± 0.2 million) was similar to the 2011 estimate and 96% above the long-term average. Estimated abundance of American wigeon (A. americana; 2.1 ± 0.1 million) was similar to the 2011 estimate and 17% below the long-term average. The estimated abundance of green-winged teal (A. crecca) was 3.5 ± 0.2 million, which was 20% above the 2011 estimate and 74% above their long-term average. The estimate of bluewinged teal abundance (A. discors) was 9.2 ± 0.4 million, which was similar to the 2011 estimate and 94% above their long-term average. The estimate for northern pintails (A. acuta; 3.5 ± 0.2 million) was 22% below the 2011 estimate, and 14% below the long-term average. The northern shoveler estimate (A. clypeata) was 5.0 ± 0.3 million, which was similar to the 2011 estimate and 111% above the long-term average. Redhead abundance (Aythya americana; 1.3 ± 0.1 million) was similar to the 2011 estimate and 89% above the long-term average. The canvasback estimate (A. valisineria; 0.8 ± 0.07 million) was similar to the 2011 estimate and 33% above the long-term average. Estimated abundance of scaup (A. affinis and A. marila combined; 5.2 ± 0.3 million) was 21% above the 2011 estimate and similar to the long-term average. Habitat conditions during the 2012 Waterfowl Breeding Population and Habitat Survey were characterized by average to below average moisture, a mild winter, and an early spring across the southern portion of the traditional and eastern survey areas. Northern habitats of the survey areas generally received average moisture and temperatures. The total pond estimate (Prairie Canada and U.S. combined) was 5.5 ± 0.2 million. This was 32% below the 2011 estimate and 9% above the long-term average (1974‒2011) of 5.1± 0.03 million ponds. The 2012 estimate of ponds in Prairie Canada was 3.9 ± 0.1 million. This was 21% below last year\u27s estimate (4.9 ± 0.2 million) and 13% above the long-term average (1961‒2011; 3.4 ± 0.03 million). The 2012 pond estimate for the north-central U.S. was 1.7 ± 0.1 million, which was 49% below last year\u27s estimate (3.2 ± 0.1 million) and similar to the long-term (1974‒2011) average. The projected mallard fall-flight index is 12.7 ± 1.2 million birds. The eastern survey area was restratifed in 2005 and is now composed of strata 51‒72. However, estimates are presented for only a portion of the eastern survey area and include data from strata 51, 52, 63, 64, 66‒68, and 70‒72. The American black duck (Anas rubripes) estimate was 0.6 ± 0.04 million, which was 11% higher than the 2011 estimate and similar to the long-term average (1990‒2011). Estimated abundance of mallards in the eastern survey area was 0.4 ± 0.1 million, which was similar to the 2011 estimate and the long-term average. Abundance estimates of green-winged teal, ring-necked ducks (Aythya collaris), goldeneyes (common [Bucephala clangula] and Barrow\u27s [B. islandica] combined), and mergansers (red-breasted [Mergus serrator], common [M. merganser], and hooded [Lophodytes cucullatus] combined) were all similar to their 2011 estimates and long-term averages