In his book Birds and Marshes of the Chesapeake Bay Country, Brooke Meanley includes a chapter on the Rusty Blackbird. The title is “Phantom of the Swampy Thickets”. Phantom is right. Anyone who sets about finding this species will soon agree. This is one species that will probably find you before you find it.
I learned this all too well when my friend (and sometime foreign correspondent to The Whooosletter), John Boughey, was visiting from England. Euphagus carolinus has been on his target list over the course of numerous trips. Bob Ringler wasn’t even able to turn one up for him. But, that’s not Bob’s fault. As Meanley said, “They slip into our territory quietly and then all of a sudden have gone on their way.”
This blackbird is usually found in swampy woods and thickets. It breeds in northern North America. We usually see them here in winter. Both sexes of Euphagus carolinus have yellow eyes. This distinguishes them from most other blackbirds that may be hanging about that time of year. Red-winged Blackbirds or Brown-headed Cowbirds have white eyes. Common Grackles eye’s are yellow, but their bodies are larger and they have obviously longer tails.
The Rusty Blackbirds’ winter plumage is more distinctive and makes them stand out among the crowd. Their body feathers are edged with rufous, rusty, or cinnamon, while the tertials are almost always rufous-fringed.
Their song (if you are ever lucky enough to hear it) has been described as being a bit like that of the Red-winged Blackbird, only not as harsh and at a slightly higher frequency. Their call is a soft “chuck”.
We here in Carroll County would be most likely to find Rusty Blackbirds wintering in small flocks. They generally forage on the ground in wet areas. When startled, they may fly up and perch in a nearby tree or shrub and begin calling. More than any other North American blackbird species, the diet of the Rusty Blackbird is made up of a large proportion of insects. This may explain why they do not overwinter farther north.
Rusty Blackbirds are monogamous. Their breeding season begins in April and ends in July. Most nest in Canada. They are generally solitary nesters, although in Newfoundland and Labrador, they have been noted to form small colonies. Nests tend to be located in a conifer about ten feet up over water. The female lays 4-5 eggs. These are light blue-green with brown spots at one end. The male brings food to the female while she broods. Hatching comes around 14 days later. Both parents feed the young who fledge in another 12 days.
The young birds form small flocks which wander about the breeding area in search of food. They molt before migrating south in winter as far as Northern Florida. Rusty Blackbirds are what are considered medium distance migrants. They travel in small flocks during the day. Fall migration usually begins in September and peaks in October. Brook Meanley thought the winter plumage of the Rusty Blackbird was “very much in tune with our October foliage.” Most of the birds will stay on their wintering grounds until February, when they will head north again, conveniently arriving back on their breeding grounds again just as the snow melts and the ground thaws.
If Rusty Blackbirds are caught out and unable to access either insect or plant material, they may resort to attacking other avian species. Small songbirds and even Wilson’s Snipe have found their way onto the menu. Interestingly, the blackbirds only eat the brains, leaving the rest of the bird untouched. Food for thought? Or would that be thought for food?
Banding records place the maximum longevity of the Rusty Blackbird at around seven or eight years. Overall, however, the species is one of the most rapidly declining in the United States. In the past 40 years, its numbers have dropped 85%-98%. Scientists have not yet figured out why.
So, if you don’t find a Rusty Blackbird, don’t feel bad. It has nothing to do with your birding skills. (Probably not anyway) The “Phantom of the Swampy Thickets” can be just that.