Bronzed Cowbird Molothrus aeneus
Flight call description Flight whistle is a very high, descending "wseeeeerz-tsuur-tsi", sometimes followed by a musical trill or gurgle. Some versions shortened to a single descending whistle. Also gives a shorter, monotone, whistled "seeeee" and a soft, low "gup". A seldom-heard rattle may also be given in flight (Jaramillo and Burke 1999).
Fig.1. Texas April 24, 2001 (MO).
Whistle song from bird in flight.
Fig. 2. Texas May 14, 2001 (WRE).
Variant whistle song from perched bird.
Fig.3. Texas May 14, 2001 (WRE).
"Gup" call from bird in flight.
Examples Diurnal
Similar species "Gup" call similar to Brown-headed Cowbird's "gup" call. Rattle call of female similar to Brown-headed's but slower and sharper (Sibley 2000). See Brown-headed and Shiny Cowbirds.
Behavior Primarily a diurnal migrant. Whistle song and "seeeee" calls are given by perched flight birds. The inconspicuous "gup" has been documented in flight but may also be given by perched birds. Based on the behavior of Brown-headed Cowbird, the rattle call presumed to be given by perched and flying birds. Not known to give any of these calls at night.