Bird Guide

Bronzed Cowbird vs Shiny Cowbird

Bronzed Cowbird (Molothrus aeneus)

Bronzed Cowbird

Molothrus aeneus

Medium63 gForest

The male bronzed cowbird is 20 cm (7.9 in) long and weighs 68 g (2.4 oz), with green-bronze, gloss-black plumage. His eyes are red in breeding season and brown otherwise. The female is 18.5 cm (7.3 in) long and weighs 56 g (2.0 oz). She is a dull black with a brown underbelly, and has brown eyes. Young birds have coloring similar to the females, with the exception of grey feather fringes.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Dennis Vollmar · CC BY 4.0
Shiny Cowbird (Molothrus bonariensis)

Shiny Cowbird

Molothrus bonariensis

Small41 gWoodland

The physical appearance of the shiny cowbird adult depends on the subspecies. Sizes range from 31–40 grams (1.1–1.4 oz) in mass and 18 cm (7.1 in) in length (M. b. minimus), to 55–65 grams (1.9–2.3 oz) in mass and 22 cm (8.7 in) in length (M. b. cabanisii). Basic adult plumage for M. b. bonariensis is black with purple-blue iridescence for males, and dusty gray-brown for females. M. b. cabanisii males have plumage similar to M. b. bonariensis, while females are paler in colouration. M. b. aequatorialis males have violet iridescence and females are dark in colour. M. b.

ID text from Wikipedia, CC BY-SA 4.0

Sonogram of the Shiny Cowbird
Recorded by Gabriele Magurno · Song · Ezeiza, Ezeiza Partido, Buenos Aires Province, Argentina · CC BY-SA 4.0
Photo: Daniel Talevi · Public domain

Where you might meet both

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Photos and recordings are credited to their authors under the licence shown. Full profiles: Bronzed Cowbird and Shiny Cowbird.