2010 Midwinter Waterfowl Survey Results

The U.S. Fish and Wildlife Service and the Maryland Department of Natural Resources (DNR) have released the results of the 2010 Midwinter Waterfowl Survey. Each winter, pilots and biologists from the two agencies count ducks, geese and swans along Maryland’s Chesapeake Bay shoreline and Atlantic coast. In January 2010, the survey teams observed 787,100 waterfowl, slightly lower than the number of waterfowl observed in January 2009.

“When pooled with results from other states, the Midwinter Waterfowl Survey provides a long-term measure of the distribution and population size of most waterfowl species wintering in the Atlantic Flyway,” said Larry Hindman, DNR Waterfowl Project Leader.

The number of mallards counted in this year’s survey (34,200) was significantly lower than 2009 (58,300). The black duck count (22,500) slightly declined from last winter, when 24,900 were counted.
“Extensive ice coverage of Chesapeake Bay waters, rivers and estuarine marshes led to reduced open water and lower numbers for several duck species this year,” Hindman said.

Overall, fewer diving ducks were counted (102,000) in 2010 than last winter (157,600). Most of this decline can be attributed to the lower numbers of redheads, canvasbacks, scaup and ruddy ducks observed. Extensive ice in the Chester River prevented diving duck use of this major wintering area favored by canvasbacks and scaup. Other environmental factors that influence the number of canvasbacks and other divers in the Chesapeake Bay are the conditions of the staging areas on the upper Mississippi River and Lake St. Claire in southern Ontario. Above average numbers of canvasbacks were recorded on surveys of those areas this year.

There was a slight increase in number of Canada geese counted by the survey crews. Despite a poor nesting season, wintering Canada geese (519,500) remained high and were likely bolstered by migrant geese pushed south by cold temperatures and snow north of Maryland.

The Midwinter Waterfowl Survey has been conducted annually throughout the United States since the early 1950s. The survey provides information on long-term trends in waterfowl populations and is the only source of population estimates for important species such as Atlantic brant and tundra swans.

source: MD DNR press release