Rusty Blackbird

INTRODUCTION:
The Rusty Blackbird is a North American species usually found in wet habitats such as wet forests when breeding from NW Alaska to extreme NE USA, and swamps while wintering in SE USA. Two subspecies share the range.
It feeds on insects in summer, whereas seeds, acorns and berries are its winter diet. It nests in a bulky structure placed in tree or shrub, usually near water.
The Rusty Blackbird is declining because it is affected by habitat loss, especially degradation of the wooded wetlands favoured by this species. It is currently listed as Vulnerable.

DESCRIPTION OF THE BIRD:
Biometrics:
Length: M: 23 cm – F: 21 cm
Wingspan: 33-38 cm
Weight: M: 46-80 g – F: 47-76,5 g

In breeding plumage, the Rusty Blackbird adult male of nominate race has black plumage overall with slight greenish gloss.
The pointed bill is black. The eyes are deep yellow. Legs and feet are black.

In non-breeding plumage, the male shows broad pale feather edges. Crown, nape and ear-coverts are rusty-brown. The supercilium is buff-brown. The underparts are buff-brown and appear black-barred. Wings, rump and tail are black with rufous edged tertials.

The Rusty Blackbird adult female in breeding plumage has slate-grey plumage, darker above with bluish-green gloss. The bare parts are like on male.
In worn plumage (fall), the slate-grey plumage is more uniform, and the glossy feathers are manly visible on the upperwing-coverts.

In non-breeding plumage, she resembles male but the feather edges are more cinnamon, whereas rump and underparts show slate-grey barring. Lores and ear-coverts are dull rufous and the supercilium is pale buff.

The juvenile has dull greyish plumage. Back and throat are tinged brown. On the wings, the feathers show narrow, pale brown edges. The eyes are dark first, soon becoming pale yellow.

SUBSPECIES AND RANGE:
The Rusty Blackbird has two subspecies.
E.c. carolinus (described above) breeds S of tundra from NW Alaska, E across Canada from North West Territories to Labrador, and S to extreme NE USA. It migrates to winter in E USA.
E.c. nigrans breeds in SE Canada (Newfoundland, Nova Scotia and New Brunswick). It migrates to E USA after breeding.

HABITAT:
The Rusty Blackbird is usually associated with shallow water throughout the year.
It breeds mainly in wet habitats such as swamps, bogs, ponds and shorelines, in both coniferous and mixed-species forests.
During winter, it frequents wooded wetlands, swamps and wet margins, but it can be found in open pastures and cultivated areas.
During the migration, it is observed in flooded forests, wet fields, at pond and lake edges, and even in roadside ditches.
This species roosts in wet, wooded areas.

CALLS AND SONGS: SOUNDS BY XENO-CANTO
The Rusty Blackbird’s usual call is a soft “chuck”. When alarmed, it gives a “chip” note and sometimes a downslurred whistle.
The male’s song is a sweet, squeaky, rising “kush-a-lee” or “chuck-la-weeeee” or also “conk-ee”. The other song does not rise in pitch. It starts with 2-3 musical notes followed by harsher, long note.
The female’s song is not well described, but she sings on the breeding grounds, usually to respond to her mate’s song.

BEHAVIOUR IN THE WILD:
The Rusty Blackbird feeds primarily on insects, seeds and berries, depending on the season. Insect diet includes many aquatic species such as caddisflies, mayflies, dragonflies and water beetles. It also takes insects on land, especially grasshoppers and other species. But the diet also includes snails, crustaceans, small fish and small salamanders caught near the wet areas.
During winter, seeds, acorns and some berries are eaten.
They may become aggressive predators when the food resources become scarce. They have been observed pursuing and killing songbirds and even larger birds such as Common Snipe, but they usually only eat the brain.

The Rusty Blackbird forages by wading in shallow water, and by walking on wet ground, solitary or in groups. But it also joins flocks of other Icteridae in dry fields.

The male displays during the breeding season. It sings while the bill is held upwards and the tail is spread. The wings are drooped (not spread). The tail is flicked upwards when the male gives its “chuck” call.
In order to respond to her mate, the female sings from the nest.
The Rusty Blackbird is monogamous. The male defends the nesting territory by singing.

This species is migratory and is a diurnal migrant. It leaves the breeding grounds in August/September, and arrives in S of the winter range in October/November, where it remains until February. The return migration occurs from mid-February. It reaches the S of the breeding range in March, and the N in May/June.
This species is recorded as accidental in Russian Far east, islands of the Bering Sea and Greenland. It is sometimes observed in N California.

The flight is strong and direct, with deep, rapid wingbeats.

REPRODUCTION OF THIS SPECIES:
The breeding season takes place from April-May to July. This species produces a single brood per season.
The Rusty Blackbird may sometimes breed in small, loose colonies, but more often in isolated pairs.
The nest is built by the female in conifer or shrub above the water, usually between 50 cm and 6 metres above the ground or the water. It is well-concealed in dense vegetation.
The bulky open cup is made of twigs, grass and Usnea lichens, cemented together with humid, rotten vegetation which then dries up. The cup is lined with grass.

The female lays 3-5 pale blue-green eggs with brown and grey spots. She incubates alone during about two weeks. She is fed by the male during this period. Exchange of food takes place on a perch, while the female performs the typical begging behaviour. The chicks are fed by both parents, and fledge about 12-14 days after hatching.

PROTECTION / THREATS / STATUS:
The Rusty Blackbird is threatened by habitat loss caused by destruction of wetlands in southern boreal forests, but also drying and changes caused by climate change. Loss of boreal forest habitat and wooded wetlands in SE USA is also an important threat.
The population is roughly estimated to number 158,000/2,000,000 individuals, but this estimate is highly uncertain.
This population is declining, and the Rusty Blackbird is currently listed as Vulnerable.