Mallard
Population: The mallard is the most common duck in the United States, with the greatest abundance between the Appalachian and Rocky mountains. Mallard populations have benefited greatly from the Conservation Reserve Program (CRP) and other grassland restoration efforts in the northern prairies of the United States, where populations have increased 100 percent above the long-term average.
Northern shoveler
Population: Northern shoveler populations have remained fairly steady since 1955, but 2007 and 2009 brought peak numbers in the 4.3-4.6-million-bird range, most likely due to favorable habitat conditions for breeding, migrating and wintering northern shovelers (U.S. Fish and Wildlife Service, 2009).
Ruddy ducks
Population: O. j. jamaicensis (North America, Central America, Caribbean) 650,000; O. j. andina, Andean ruddy duck (High Andes of Colombia) 2,500-10,000; O. j. ferrugineaPeruvian ruddy duck (Neotropics) 25,000-100,000 (Rose and Scott, 1994).
Hooded mergansers
Population: Hooded mergansers are most common in the Great Lakes region and current information suggests a stable, possibly increasing population in some areas. However, data on population size and status are tenuous due to the secretive nature of this species. Historically, populations likely suffered from habitat loss.
http://www.ducks.org/hunting/waterfowl-id/ruddy-duck#ad-image-0
http://www.npwrc.usgs.gov/resource/birds/maldec/
Are Mallards Declining in North America?
Douglas H. Johnson and Terry L. Shaffer
Whether mallard (Anas platyrhynchos) numbers have declined in recent years has been a subject of concern and debate among waterfowl biologists, wildlife managers, and administrators. Further controversy surrounds the reason for the presumed decline. One opinion holds that the decline, if it exists, is simply a reflection of a dry period, with fewer ponds available to support mallards. The opposing view is that mallards have declined more severely than wetland numbers, and have not responded to subsequent improvements in wetlands.
Verifying a decline seems relatively straightforward; after all, waterfowl have been counted in extensive and systematic surveys of major North American breeding grounds every year since 1955. Resolution of the debate is confounded, however, by the fact that the surveys were expanded several times in early years. Also, surveys began during what was apparently a wet period, with more basins containing water than have been recorded since; thus, mallard estimates from initial surveys may not be a representative starting point from which to draw comparisons.
We address 3 primary questions: (1) have numbers of breeding mallards in the surveyed area declined since the mid-1950s; (2) if so , are the changes due to variation in the number of wet ponds; and (3) has the relationship between mallard numbers and number of wet ponds changed in recent years?
…
The mallard counts themselves were consistent with a real decline, although the series was too short to be definitive. The pattern of correlations with pond numbers has weakened from 1955-1970 to 1971-1985, suggesting that mallards are no longer filling their primary habitat to the former extent. …
Taken together, the 3 approaches suggest a decline in the North American mallard population that is not simply a reflection of reduced numbers of wet ponds. We do not address the question of whether the decline is due to increased mortality or reduced productivity.
While duck populations in the United States and Canada have declined 6 percent in the last year, the countries' overall duck population still exceeds the long-term average by 33 percent, according to a briefing from the U.S. Fish and Wildlife Service (FWS).
FWS's 2013 report on trends in duck breeding populations indicated there are an estimated 45.6 million ducks in the survey areas, which encompasses north-central United States, south-central and northern Canada, and Alaska. The duck estimate is less than last year's estimate of 48.6 million birds.
Particulars of the 2013 duck population survey include:
· Estimated mallard abundance is 10.4 million birds, similar to the 2012 estimate of 10.6 million birds and 36 percent above the long-term average.
· Blue-winged teal estimated abundance is 7.7 million. Although this is 16 percent below the 2012 estimate of 9.2 million, the blue-wing population is 60 percent above the long-term average. Similarly, the green-winged teal estimate of 3.1 million is 12 percent below last year but still 51 percent above their long-term average.
· The northern pintail estimate of 3.3 million is similar to the 2012 estimate of 3.5 million and 17 percent below the long-term average.
· Estimated abundance of American wigeon is 2.6 million and 23 percent above the 2012 estimate and similar to the long-term average.
· The combined lesser and greater scaup estimate of 4.2 million decreased 20 percent from last year and is 17 percent below the long-term average of 5 million. The canvasback estimate of 787,000 is similar to the 2012 estimate and 37 percent above the long-term average.
Long-feared decline in duck populations is already beginning, biologist says
Hunters have heard the stories of declining wetlands in the breeding grounds for years, and perhaps have become numb to the threats. But Reynolds feels we've already begun to see a decline in waterfowl production.
Last summer, Reynolds explained, the prairie pothole region had a record number of breeding ducks, which, of course, is a good thing. But the pond counts declined 35 percent.
"I think the production was much lower," he said. That would be the logical conclusion, but Reynolds also has anecdotal evidence to back up his theory. He explained that this year, he had twice as many adult ducks in his bags as juveniles. Last season, the breakdown was about 50/50, he said.
That's an indication that all those breeding pairs didn't have a tremendous amount of success producing ducklings last summer.
"What has saved us in recent years has been the incredible amount of precipitation we've seen on the breeding grounds," Reynolds said. "But what happens when we return to just average (precipitation)? What if we lose another 25 percent of our ponds this year? We'll have a decline at least as rapidly as we had in the '80s."
http://www.nola.com/outdoors/index.ssf/2013/02/long-feared_decline_in_duck_po.html