Measurements
Both Sexes
- Length
- 7.1 in
18 cm - Weight
- 1.1–1.4 oz
31–40 g
Other Names
- Vacher luisant (French)
- Tordo renegrido, Tordo vaquero, Tordo lustroso (Spanish)
Cool Facts
- The Shiny Cowbird first reached the United States in 1985 when a single male was seen in the Florida Keys. By the early 1990s they were considered permanent residents in southern Florida. In the next few years individual Shiny Cowbirds were seen as far away as Maine and Nova Scotia.
- The Shiny Cowbird began expanding its range out of South America around 1900. Its spread was assisted by the removal of natural forest cover on Caribbean islands.
- The Shiny Cowbird is a widespread species in South America, and seven different subspecies have been described. The northern form, the one that made it to Florida, is the smallest.
Habitat
Grassland
Open or semiopen habitats, especially agricultural areas with patches of trees and shrubs. Suburbs, lawns, and at bird feeders.
Food
Insects
Insects, spiders, and grain.
Nesting
Nesting Facts
- Egg Description
- White or pale gray. May be marked with brownish spots.
- Condition at Hatching
- Helpless with sparse pale gray down.
Nest Description
None. Lays eggs in nests of other bird species.
Nest Placement
Tree
Behavior
Ground Forager
Forages while walking on ground, scratches ground with one foot, feeds in trees, or with large animals. Often feeds in mixed flocks of other blackbirds.
Conservation
Least Concern
Expanding range. Conservation concerns mostly about effect of cowbird parasitism on hosts. Parasitism by Shiny Cowbirds may have caused declines in endangered Yellow-shouldered Blackbird and Puerto Rican Vireo populations in Puerto Rico.
Credits
- Lowther, P., and W. Post. 1999. Shiny Cowbird (Molothrus bonariensis). In The Birds of North America, No. 399 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.