Bronzed Cowbird (Molothrus aeneus) [XC440554]
by Richard E. Webster from Ca\u00f1\u00f3n Cieneguilla, Alamos, Sonora, MX, Mexico (rattle)
Bronzed Cowbird (Molothrus aeneus) [XC316992]
by Richard E. Webster from Santa Ana, Santa Ana., El Salvador (call)
Subspecies
Molothrus aeneus (Sibley and Monroe 1990, 1993, AOU 1998) is retained as a species contra Stotz et al. (1996) who split it into Bronzed Cowbird (Molothrus aeneus) and Molothrus armenti.
Formerly placed in genus Tangavius, but such treatment not supported by molecular-genetic findings. Analyses of mitochondrial DNA indicate closest relationship with Screaming Cowbird (Molothrus rufoaxillaris) and Giant Cowbird (Molothrus oryzivorus). Often considered conspecific with Molothrus armenti, but shows more marked sexual dichromatism and also differs vocally.
The following 4 subspecies are recognised:
loyei Parkes & Blake, 1965 - Breeds from south-western USA (southern California, Arizona, New Mexico and western Texas) southern in western Mexico to Nayarit and northern Baja California.
aeneus (Wagler, 1829) - Breeds in southern USA (southern Texas, Louisiana and Florida) and from eastern and central Mexico south, including nearby islands (e.g. Cozumel I), to central Panama.
assimilis (Nelson, 1900) - South-western Mexico from Jalisco south to Chiapas.
armenti Cabanis, 1851 - Colombia. Considered by some authors to be a distinct species, Bronze-brown Cowbird (Molothrus armenti).
BirdLife International Species Factsheet