grosbeak with berry
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female rose-breasted grosbeak with berry -
worth viewing LARGE!
The Rose-breasted Grosbeak hybridizes with the Black-headed Grosbeak where their ranges overlap in the Great Plains. Hybrids can look like either parent species, or be intermediate in pattern, with various combinations of pink, orange, and black. Hybridization occurs most often where the densities of both species are low, and only rarely when densities are high.
In areas of overlap with the Black-headed Grosbeak, male Rose-breasted Grosbeaks responded equally to songs of both species. When presented with mounted birds, however, they attacked the Rose-breasted Grosbeak mount more. The males directed their attacks primarily at the white rump and flanks of the model, suggesting that the white rump is a more important stimulus than the red chest.
The nest of the Rose-breasted Grosbeak is so thinly constructed that eggs often can be seen from below through the nest.
The male Rose-breasted Grosbeak participates in incubation of the eggs, accounting for about 1/3 of the time during the day (the female incubates over night). Both sexes sing quietly to each other when they exchange places. The male will sing his normal song while near or actually on the nest.