Friday, August 12, 2011

Ducks need grass too


Drake Ruddy Duck displaying in late July near Grasslands National Park, Sage Herriot

This wet spring and summer has made for as ducky a breeding season as I can remember. There are ponds and sloughs everywhere on the prairie and in late June and July every one of them seemed to host a brood of mallards, wigeon, scaup or redhead.

I often report alarming and discouraging statistics in this space, but here are some we can all celebrate. According to an outdoor column I read today, U.S. Fish & Wildlife waterfowl surveys are estimating 45.6 million breeding ducks in the North American population this year. That means they believe we will have 11 percent more ducks than they estimated last year (40.9 million) during the spring survey. They have been keeping data on this since 1955 and this year’s estimate is 35 percent above the long term average! In fifty-six years, the estimate has exceeded 40 million only five times. (See below for the U.S. Fish and Wildlife estimates on the common duck species that breed on the northern Great Plains.)

According to this same column, the aerial pond counts in the United States and Canada showed 8.1 million ponds, a 22 percent increase from last year’s estimate and 62 percent above the long-term average. Only one other time in the history of the survey has the figure gone beyond 8 million.


Redhead landing at a dugout near Lanigan

As terrific as these figures are (you knew I would have something to qualify all the good news), they would have been even better if our wetlands were surrounded by wider margins of grassland. Too many of our sloughs are cultivated right up to the water’s edge. Ducks don’t ask for a lot of grassland habitat, but many species need to have some upland grass beyond the water’s edge to nest in.

Unfortunately, nesting cover has been declining in both the Canadian provinces and the American states on the northern Great Plains. In the U.S., grassland formerly protected by the Conservation Reserve Program has recently been converted to cropland in response to high corn prices driven by federal subsidies for biofuel production. According to Ducks Unlimited, North Dakota alone has lost 22 percent of its CRP acres since 2007. They estimate that another 387,000 acres will be lost in 2010-2011 and more than 1 million acres will be lost in 2012-13. (For more on this concern about losing native grassland in the duck-breeding prairies of the northern states, see this excellent column by Minneapolis Star-Tribune writer, Dennis Anderson.)


Ring-necked Duck pair in early spring, beaver pond in Upper Indian Head Creek

All the water we have this year and are likely to still have in the next couple of years could produce even more waterfowl if Canadian and American governments would stop subsidizing biofuels and instead begin to subsidize carbon sequestration in perennial grassland.

Having said that, these reports of high duck numbers and pond counts are as encouraging as anything I have heard this year in conservation circles. Like many prairie naturalists, I'm feeling grateful for the recovery of our prairie waterfowl, and looking forward to seeing some large flocks this September and October as they begin to gather for the flight south.


Northern pintail near Strawberry Lake Community Pasture

Here is a breakdown of estimates for this year species by species:

Mallards — 9 percent increase compared with 2010 estimates; 22 percent greater than long-term average.

Gadwalls — 9 percent increase compared with 2010 estimates; 80 percent greater than long-term average.

Wigeons — 14 percent decrease compared with 2010 estimates; 20 percent less than long-term average.

Green-winged teal — 17 percent decrease compared with 2010 estimates; 47 percent greater than long-term average.

Blue-winged teal — 41 percent increase compared with 2010 estimates; 91 percent greater than long-term average.

Shoveler — 14 percent increase compared with 2010 estimates; 98 percent greater than long-term average.

Pintail — 26 percent increase compared with 2010 estimates; 10 percent greater than long-term average.

Redheads — 27 percent increase compared with 2010 estimates; 106 percent greater than long-term average.

Canvasback — 18 percent increase compared with 2010 estimates; 21 percent greater than long-term average.

Scaup — 2 percent increase compared with 2010 estimates; 15 percent less than long-term average.

Source: U.S. Fish & Wildlife Service

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