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Rusty Blackbird

 

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Scientific Name: Euphagus carolinus

Nest Type: Cup

Nest Location: Deciduous tree, shrubs; 2-8'

Clutch Size: 4-5

Food: Insects, seeds

Foraging Guild: Ground gleaner

The Rusty Blackbird has a relatively large breeding distribution primarily confined to the boreal zone of Canada. In Minnesota, the species is a rare nesting bird in northern Cook, Lake, and St. Louis Counties (Janssen 1987). The species is a common spring migrant in Minnesota and a a relatively common fall migrant. The spring migration period is generally from mid-March through mid-May, with most migrants occurring during the month of April. Fall migration is from early September through early December, with most of the migrants being found in the month of October. The species occasionally occurs as a winter visitant in the southern portion of the state (Janssen 1987). Rusty Blackbirds winter in the southern U.S., and are usually found in or near bottomlands.

On the breeding grounds, the species is almost always found associated with water such as woodland ponds, bogs, flooded lakes, stream edges, or habitat created by beaver dams (Kennard 1920, Bent 1958, Erskine 1977, Brewer et al. 1991). Hence, the species was classified as a riparian associated species. Brewer et al. (1991) noted that its territories seem to be rather large because nest sites are generally separated by .8 km or more.

The Rusty Blackbird generally constructs its nest in dense undergrowth of evergreens, but deciduous shrub vegetation is also used, usually in association with water. The nest is generally less than 10 ft above ground, and 4-5 eggs are typically laid (DeGraaf et al. 1991). The species is highly omnivorous and will forage on insects, seeds, grains, and fruit, depending on availability (Martin et al. 1951). During the summer the diet is more insectivorous, while in the winter more grains and fruits are taken.

In Minnesota, no information is available on general population trends of the species because of its rarity. The species has likely always been relatively rare in Minnesota because its primary breeding habitat is farther north throughout Canada. However, because the species is associated with water edges created by beaver dams, it may have been more common in the past. It is unlikely that forest harvesting or management on the breeding grounds had a major effect on the species. Reductions in beaver populations and development of lakeshore property have likely had a greater effect on the species in Minnesota.