Saturday, March 29, 2008

Rusty Blackbird migration

Right now there are relatively large numbers of Rusty Blackbirds in our general area. Of course, at this stage in the migration there are very large numbers of blackbirds in general, so the Rusties don’t necessarily stand out. It takes some effort and attention to see them. And it's worth doing, too, especially since there is now a lot of speculation about population declines of the species. But today I saw about 700 individuals in less than 3 hours of actively looking for them, so they're certainly present to be found at the moment.

Rusty Blackbirds strongly favor swampy areas at this season. A swamp, by a birder’s definition, is an area with trees standing in or immediately next to slow-moving or still water. It’s different from a marsh (a more open habitat with mostly grasses or other low plants in standing water) and different from a muddy field or a pond or lake. So -- trees and water, that’s the combination. There are a lot of Rusties along the road in from Rt. 2 to Crane Creek / Magee Marsh, especially around the BSBO center (we saw several out the windows there this afternoon) and in the swampy woods just beyond the Sportsmen’s Migratory Bird Center, past the hawkwatch tower. There are fair numbers in the woodlot near the old parking lot at Ottawa Natl Wildlife Refuge, and in the woodlot at the end of the road at Metzger Marsh. The biggest numbers I saw today (Saturday March 29) were south of Route 2 along Toussaint Creek. Where Benton-Carroll Road crosses the creek, about 2 miles south of Route 2, there were at least 250 Rusty Blackbirds associating with even larger numbers of Common Grackles and Red-winged Blackbirds (and smaller numbers of Brown-headed Cowbirds). I also saw a few Rusties with blackbird flocks farther south on Benton-Carroll Road and on other area roads, foraging out in flooded fields; this is another kind of situation where you find them but it doesn’t seem to be one of their favorites.

When they’re with mixed groups of other blackbirds, Rusties are sort of inconspicuous. Often they’re down foraging quietly at the water’s edge, or wading in very shallow water, singly or in little clusters of their own kind. The males are black with just a touch of iridescence and the females are mostly dark slaty. They’re a little longer-tailed than Red-winged Blackbirds but distinctly shorter-tailed than Common Grackles (and slightly shorter-tailed than Brewer’s Blackbird, a rarity here). One of the best ways to find them is by their song, a "rusty-hinge" sound, ksh-tsh-leeee, the last note high and creaking. Now, at the end of March and beginning of April, you can hear this sound regularly around the edges of swampy woods in the Magee - Crane Creek area. Numbers of Rusty Blackbirds will drop off sharply by late April, and by early May they’ll be hard to find. Right now is a good time to focus on getting better acquainted with this generally uncommon bird.

1 comment:

Anonymous said...

We have a large number of assorted blackbirds that migrate through Verdigris Oklahoma every year. They just started here again on 11/03/08. They take the same path every year. Tens of Thousands at a time in strings as far as you can see over the same path for about 1 week, every evening. They come right over a golf course here in Verdigris Oklahoma.

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