Rose-breasted Grosbeak
Pheucticus ludovicianus

Migratory Status: Neotropical migrant

PIF Population Estimate: 4 600 000

Percent of western hemisphere population breeding in boreal forest: <25%

BAM Effective Detection Radius (m) : 94.69

PIF Maximum Detection Distance (m) : 125

Canadian BBS Population trend: -1.9 (-2.8 to -1.0)

Life History

The Rose-breasted Grosbeak is a striking bird both for its appearance and for its song, which consists of 15 to 23 richly sung repeated syllables creating a melody that rivals that of the American Robin (Turdus migratorius) and Scarlet Tanager (Piranga olivacea). Occupying mature and secondary deciduous and mixed-forest types, this medium-sized finch is a common sight across central and eastern Canada during the breeding season.

Males in definitive alternate (i.e., breeding) plumage are conspicuous in appearance, with a black hood, bib, and back contrasting strongly against a white breast, belly, and a thick whitish beak. But the feature that best identifies the males and provides their namesake is the reddish-pink triangle on the breast. While males are ready to breed after their first year, they experience delayed plumage maturation, and as a result it can take three or more years for a male to reach full breeding plumage. Immature males generally arrive on breeding grounds later than males in full-breeding plumage, and so have trouble finding and holding a territory and thus a mate.

While you would never have trouble identifying a male Rose-breasted Grosbeak, females are relatively hard to identify because they are striped and brown. Where their range overlaps with the Black-headed Grosbeak (Pheucticus melanocephalus), a closely related species, females of each are easily confused because they are so similar in appearance. Interestingly, the two species can successfully hybridize, however hybrids (which can look like either species or a combination of both) have a lower hatching success rate.

Breeding range extends from north eastern British Columbia and the Yukon, east through the central portion of the prairie provinces and the southern portions of Ontario and Quebec into the Maritimes. Outside of Canada, the breeding range extends into the north, central and eastern United States. Populations of Rose-breasted Grosbeaks can be found overwintering in open forests and second growth woodlands along the Pacific and Gulf Coasts of Mexico, southward through Central America and into the northern countries of South America.

Once a targeted pest species because they were thought to damage crops, Rose-breasted Grosbeaks are now recognized as beneficial because they consume potato beetle larvae (Leptinotarsa decemlineata) and other insects that damage crops. Insects, fruits, buds, and seeds all make up a large portion of this species’ diet.

Reference(s)

Burke, D. M., and E. Nol. 2000. Landscape and fragment size effects on reproductive success of forest-breeding birds in Ontario, Ecological Applications, 10(6):1749-1761.

Wyatt, V. E., and C. M. Francis. 2002. Rose-breasted Grosbeak (Pheucticus ludovicianus), The Birds of North America Online, . A. Poole, Ed. Ithaca: Cornell Laboratory of Ornithology; Retrieved from The Birds of North America Online database: http://bna.birds.cornell.edu/bna/species/692