Bronzed Cowbird (Molothrus aeneus aeneus)
9 April 2009, Grande Island, Jefferson Parish, Louisiana.
This relative of our familiar Brown-headed Cowbird (Molothrus ater) is
confined to the southern states and tropics. Like the Brown-headed Cowbird
it is an obligate brood parasite, laying its eggs in the nests of other
birds, often to the detriment of the host species.
A variety of hosts have been recorded, but the Bronzed Cowbird is said to
favor orioles. A recent decline in the number of Northern Cardinals in the
New Orleans area has been linked to an increase in Bronzed Cowbirds, but
evidence for this is unclear.
This species is slightly larger than the Brown-headed Cowbird and is
distinguished by its red eyes. Formerly it went under the name "Red-eyed
This species has been expanding its range northward and is now locally
distributed in Louisiana where it was first recorded in 1961. It has
evidently benefited from the clearing of the original native vegetation for
agriculture and human settlement.
Four subspecies are recognized. This is the nominate race which occurs
from Southern Texas to Panama (plus an isolated outlying population in
southeastern Louisiana). It differs from other races in its bronzy (not
violet) rump. In this population, females are similar to males although
smaller and lack the ruff around the neck. I believe this individual is a
Digiscoped with Panasonic DMC-LZ5 | Nikon FieldScope 3 | 30X WA | hand-held