- 7.1–8.3 in - 11.4–13 in - 1.4–1.7 oz - Smaller than an
American Robin; larger than a House Finch. - Cardinal à poitrine
rose (French) - Picogrueso pechirrosado (Spanish) - In parts of
the Great Plains, the Rose-breasted Grosbeak hybridizes with its
close relative, the Black-headed Grosbeak. Hybrids can look like
either parent species or be intermediate in pattern, with
various combinations of pink, orange, and black. The two
grosbeak species are most likely to hybridize in areas where
both species are scarce. - Researchers used mounted specimens of
male Rose-breasted Grosbeaks to explore aggressive behavior.
Live male birds attacked the white rump and flanks of the
models, suggesting that the white markings are more important
than the red chest in stimulating aggression. - Rose-breasted
Grosbeaks build such flimsy nests that eggs are often visible
from below through the nest bottom. - The male Rose-breasted
Grosbeak takes a turn incubating the eggs for several hours
during the day, while the female incubate