Thursday, May 28, 2020

Black-headed Grosbeak

On 23 May 2020, we banded a pair of Black-headed Grosbeaks in our Olympia backyard. The first photo is of a male, the second is a female. Black-headed Grosbeaks are common Western birds that interbreed with Rose-breasted Grosbeaks where their ranges overlaps. The males look quite distinct, but the females can be similar. Note that the female tend to have a much less streaky breast.  

During our traels, we often hear Black-headed Grosbeaks singing.They sound to me like a jazzed-up Amerian Robin.  Males sing for territorial defense. Females usually sing a toned down version of the male song. Female song is used to communicate with mates and nestlings. Curiously, females occasionally sing full male song, "apparently to deceive mates about the presence of intruders and force greater nest attentiveness” (Ortega and Hill 2020).

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