Tuesday, November 03, 2009
Waterfowl ups and downs
On Sunday, I made a quick trip to nearby Pinchot State Park to look for winter waterfowl. So that explains why I’m foisting a bad photo of a pied-billed grebe in winter plumage upon readers. In addition to this little grebe, I also found a small flock of buffleheads and ring-necked ducks, but I didn’t find anything else other than the usual mallards and Canada geese.
Over the past 10-15 years or so, numbers of waterfowl have declined, in some areas precipitously. The worst decline is in Asia, where 62% of species show declines, but even in North America, 37% of species have declined.
Loss of wetland breeding habitat is the main reason, though for some species over-harvesting is also a factor. Certain species are also more affected than others—brant, American black duck and scaup (both greater and lesser but especially greater) are among the hardest hit. The black duck was once the most abundant freshwater species but is now increasingly uncommon. Droughts in the past few years have also taken a toll on breeding success, even where wetlands remain.
The situation in the U.S. isn’t completely dire. A couple of good breeding seasons can go a long way towards improving a population. Waterfowl tend to have large clutches, so in a good year a successful pair can fledge as many as 8-10 young. Estimates for 2009 indicate this past breeding season was a good one, certainly better than 2008.
The USFWS publishes a status report on waterfowl populations every year and in the current report found that green-winged teal are at an all-time high and blue-winged teal are at their second highest numbers. Redheads are also on the plus side. Even canvasback, a species that has declined especially in the east, are about 35% above the 2008 estimate. Scaup remains some 20% below the long-term average but is doing better than last year.
American wigeon, northern pintail, scoters and scaup are all still well below the long-term (54 years) averages. To read the entire 79-page Waterfowl Population Status, 2009, click here. You’ll find a lot of interesting reading in there.
I'm glad the news is better this year, but that didn't translate into lots of waterfowl sightings for me this past weekend. Maybe the upcoming week will be better.