Friday, November 4, 2011

Rusty Blackbirds: Northwest Ohio is important to their survival

Rusty Blackbird at the BSBO passerine banding station at Navarre Marsh, Ottawa NWR, in October 2011.  With their rich rusty feather edges, these fall birds are easier to pick out and identify than they will be in spring, when the edges are largely worn away.  Photo by Julie A. Shieldcastle.

On the afternoon of Thursday Nov. 3, Paul Baicich and I encountered good numbers of Rusty Blackbirds at Magee Marsh.  While walking the trails behind the Sportsmen's Migratory Bird Center we had several flocks of 15 to 50 birds each; I estimated a total of about 270 Rusties in the area.  Later, stopping by the Black Swamp Bird Observatory half a mile to the south, I saw another 40 or so in the woods near the building.

Numbers like these are not at all unusual for this immediate area; in early spring and late fall, we frequently see well over 1000 Rusty Blackbirds in a day.  Elsewhere in the range of the species, however, such counts are becoming increasingly rare.  There is serious concern about the status of Rusty Blackbird, which evidently has suffered a major population decline in recent decades.  (For more information, see this link.)

Northwestern Ohio is among the few remaining areas of the continent where large concentrations of Rusty Blackbirds still can be found consistently during migration. It's likely that this region always was important to the species. In centuries past, a vast area of northwest Ohio was occupied by the Great Black Swamp and the western Lake Erie marshes, and these wetlands would have provided perfect stopover habitat for Rusty Blackbird when the species was still abundant. Now the wetlands and the Rusty Blackbird population are both greatly diminished, but the species still concentrates here in what remains of the habitat. Particularly good swampy woods and marsh edges can be found on several areas administered by the Ohio DNR - Division of Wildlife, such as Magee Marsh, Metzger Marsh, Mallard Club, Toussaint, Little Portage, Pipe Creek, Pickerel Creek, Resthaven, and Willow Point. Ottawa National Wildlife Refuge also has outstanding habitat, and the large contiguous area made up of Ottawa, Magee, and Metzger may be especially valuable. Two Ohio state parks, Maumee Bay and East Harbor, also hold significant numbers of Rusty Blackbirds during migration. Birders should recognize the value of all of these protected areas to the survival of this declining species, and show our support for the agencies responsible for these lands.

For birders who lack experience with Rusty Blackbirds, this is the best time of year to get to know them. They're easy to identify right now, as virtually all show very strong rusty feather edges (by spring, with those edges largely worn away, most will be dull black or blackish gray, and more likely to be overlooked). Although flocks may be seen feeding in open fields, they concentrate in swampy woods. Flocks in flight are often silent, not noisy like Common Grackles or Red-winged Blackbirds; they tend to be in looser flocks than either of those two species, and they are shorter-tailed than grackles. They may associate with other blackbirds or with starlings, but they tend to maintain their own sub-flocks within larger groups. When they are among large numbers of other blackbirds, their distinctive, creaking "kssh-dleeee" is often the first giveaway that Rusty Blackbirds are present.

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