Rusty Blackbirds (Euphagus carolensis) have long been an overlooked species. A medium-sized blackbird, they’ve never been as iconic as Redwings in the East or Brewer’s Blackbirds in the West. Partly it’s their lack of any signal feature like the Redwing’s shoulder patches, but also it’s their retiring habits. Rusties are not birds of roadside ditches, ponds, or parks. They much prefer more inaccessible swamps and bogs. They breed in spruce bogs all across Alaska and northern Canada, and then they re-create that habitat choice by wintering in riverine swamps of the coastal plain and the Mississippi Valley.
Rusties, as most birders call them, are not your typical blackbird in other ways. Rusties aren’t summer breeders here like Redwings or Grackles; ours breed in Canada and migrate through. They also move south later (October through December) and return north earlier (February and March) than most blackbirds. Big flocks of fall migrants can show up at the Lake Erie marshes in November and December, long after other blackbirds have headed south. Formerly there were wintering flocks in central Ohio, but now they’ve become a rare, unpredictable part of our winter avifauna.
How do you know when you’ve stumbled on some Rusties? They look and sound different from Redwings and Grackles: be alert for a brown-tinged blackbird with a light eye and a soft “chuck” note. Winter birds often have brown or rusty tones in their plumage. They usually don’t come in huge flocks; often they are in groups of 20 birds or less here in central Ohio. I really key on their behaviors: Rusties like to root around in puddles and wet leaf litter. If you see a blackbird wading around in a shallow pool, give it a second look. David Sibley gives a few more subtle marks at his Web site.
Where should you be alert for these tricksters? In fall migration they can appear anywhere—swamps, fields, farm feedlots—and can be mixed in with other blackbirds in huge flocks. But as the winter wears on, Rusties home in on their favorite habitats: wooded swamps. In states south of us, that usually means flooded river swamps. Rusties seem to associate with riparian swamps with lots of oaks, mostly because acorns are an emergency winter food for them if invertebrates become scarce. Here in central Ohio, such oak-dominated swamps have always been rare, so Rusties have adapted to human-created swamps. The areas around Buckeye Lake were formerly their local nirvana, and the swampy woodlands of the Hebron Fish Hatchery are still a good place to look for them. The wetland swamps of Big Island and Delaware Wildlife Areas are also good. Our own Calamus Swamp near Circleville is another very good spot for them, and I’ve seen a few at many of the small swamp forest remnants in parks from Grove City to Dublin, including Sawmill Wetlands.
Now for the bad news. Your chances for seeing Rusties are not good and getting worse by the year. Most of the reasons are summarized by Birdsource on their Web site. These swamp blackbirds have seen declines of nearly ten percent yearly over the past several decades. We’re not sure of the cause of this disappearance. Their habitat seems largely unchanged in both Canada and the southern US, but something subtle has shifted. Fortunately, human awareness of the problem is growing. Some conservation groups like Audubon are now focusing on Rusty Blackbirds, and there has even been a Rusty Blackbird Roundup, a semi-organized census of the birds across the eastern US in early-mid February. Now, that survey is expanding to cover most of the species’ migration and wintering stages. You want to keep an eye out for Rusties, since our observations may help biologists crack the mystery of its decline.