Friday, May 15, 2009

Grass, Sky, Song Illustrated:
"Death By a Thousand Cuts"

Source: U.S. Fish & Wildlife
The bobolink, a bird of moist meadows that breeds in many states and provinces across North America, is declining in part because of pesticide use in its winter range in South America. Up here, we can help bobolinks out by not mowing fields where they nest until at least July 15.

image courtesy of Northern Plains Wildlife Research Center

I open this chapter talking about one of the "thousand cuts" that are killing grassland birds. The list of predators that birds on remnant grasslands have to contend with is long and varied, but it was a shock to discover that white-tailed deer is on that roster. The image posted above shows a deer with its muzzle in a nest of seven-day old Savannah sparrows. It's a video capture from research done by The Northern Prairie Wildlife Research Center in North Dakota proving that white-tailed deer are eating grassland bird nestlings. Here is a link to the research paper.

Bridgit Stutchbury

Habitat fragmentation gets a lot of attention in the world of bird decline and so in this chapter I use some of Bridget Stutchbury's work on the effects of fragmentation on forest songbirds to speculate on how the same factors may be harming grassland birds. Her take on how fragmentation affects birds has more to do with social behavior and extra-pair copulation than vulnerability to predators and cowbirds. Here is one of the papers she published on gap-crossing and fragmentation.

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