Rusty Blackbird

The Rusty Blackbird (Euphagus carolinus), a medium-sized member of the New World blackbird family, is a species that exhibits sexual dimorphism. The male is cloaked in black plumage with a subtle green and purple sheen, while the female is a more subdued grey. Both sexes possess a pointed bill and pale yellow eyes. The name "Rusty" is derived from the brownish tinge of their winter feathers, a seasonal wardrobe change from their sleeker breeding attire.

Identification Tips

When identifying the Rusty Blackbird, look for the distinctive pale yellow eye and the pointed bill. In comparison to its relative, the Brewer's Blackbird, the Rusty Blackbird has a shorter bill, and the male's head lacks the iridescent green hue found in Brewer's.

Habitat

The Rusty Blackbird breeds in the wet, forested areas of the boreal forest and muskeg across northern Canada. It prefers the edges of ponds and wetlands, where it often nests in trees or dense shrubs, sometimes directly over water.

Distribution

During the breeding season, these birds can be found across Canada, New England, the Upper Peninsula of Michigan, the Adirondack Mountains in New York, and Alaska. Come winter, they migrate southeast to the United States, with some venturing into Mexico and rare sightings in Greenland and Russian Siberia.

Behaviour

Rusty Blackbirds forage on wet ground or in shallow water, flipping leaves and tearing at submerged vegetation to find insects, small fish, and seeds. They are known to feed in flocks during migration and winter, occasionally joining other blackbird species. Their migration is characterized by a slow departure from the north in autumn and a more rapid return in spring.

Song & Calls

The Rusty Blackbird is relatively silent during fall migration and winter but becomes more vocal towards the end of winter and into spring. Both males and females sing, producing a melody of gurgling and high-pitched squeaks, especially on warmer days.

Breeding

These birds are early nesters in the boreal forest, with a tendency to linger in the north to complete their molt. They form cup nests at the edge of water bodies, where emerging dragonflies and their larvae serve as important food sources for their young.

Similar Species

The Rusty Blackbird can be confused with the Brewer's Blackbird, but differences in bill length and head coloration can help distinguish the two. The Brewer's male has a longer bill and an iridescent green head, unlike the Rusty Blackbird.

Diet and Feeding

The diet of the Rusty Blackbird is varied, including insects, small fish, and seeds. They have a particular affinity for the mast of small-acorn producing oaks and, in some regions, pecans. Rarely, they may predate on small passerine birds and have been known to take species as large as the Wilson's snipe.

Conservation status

The Rusty Blackbird is currently classified as Vulnerable by the IUCN. Its populations have experienced a precipitous decline, likely due to habitat loss from industrial development, hydroelectric projects, and deforestation. Mercury contamination and the effects of acid rain on calcium-rich invertebrates, a key food source, may also contribute to their decline. Conservation efforts are being bolstered by citizen science projects and the International Rusty Blackbird Working Group to better understand and mitigate these threats.