Bird of the Month: October 2002

Rose-breasted Grosbeak
Pheucticus ludovicianus

by David Fix

Gaudy plumage causes a birder’s first good look at a male Rose-breasted Grosbeak to sear an image persisting long in memory.  The less showy immature males and soberly-patterned females, while hardly a riveting sight, appeal with their heavy bills, intricate plumage patterns, and general bull-headed appearance.  This is a species few Western birders will encounter early in their experience.  The humblest field guide will instruct one that Rose-breasted Grosbeak is a bird expected only east of the Rockies.  Even though its portrait is emblazoned upon innumerable bags of birdseed sold in California, it is only infrequently seen here.  True enough, but alert observers on the watch for unusual visitors to their backyard feeders may be rewarded with the sight of one of these birds.

Rose-breasted Grosbeaks actually have come to be known as regular visitors to California.  They occur in very small numbers nearly throughout the year.  This having been said, the situation can be qualified with respect to season.  In our Redwood Region, from one (occasionally none) to several spring ‘vagrants’ appear nearly every year near the tail end of the spring migration of routine West Coast songbirds.  Commonly, these strays remain a day, a week perhaps, and then disappear.  A few have lingered at feeders or on apparent song territories well into mid-summer.  Although rare, this species has a long history of appearing in the fall migration, chiefly from mid-September through October, single birds popping up in brushy coastal woodlots or at feeding stations.  Finally, once in awhile a Rose-breasted Grosbeak will spend the winter--or most of it--establishing a regular daily routine at a favored birdfeeder.  Should such a lingerer occur within a local Christmas Bird Count circle, and should it be seen on the count, it is immediately among the ‘best birds’ to be found...‘list unseen’!

All of you who feed wild birds here should be aware that Rose-breasted Grosbeaks do show up.  Watch for one to drop in at your feeding station!  What do you look for?  Look for a bird resembling a Black-headed Grosbeak in size, build, voice and mannerisms—but with different colors.  Adult males have a remarkable inverted triangle of rose-red on upper breast, a white lower breast and rump, and a flash of red in the underwing;  they lack the intense burnt-orange color of the closely-related male Black-headed.  Females look almost like the female Black-headed, but lack the warm buff underparts of that species, instead showing coarse and conspicuous dark streaking across the breast.  Their supercilium (line above the eye) and nape are whitish rather than buff.  A supporting field mark for each sex is that the entire bill of Rose-breasted Grosbeak is pale;  in Black-headed Grosbeak, the upper mandible is darker.  Bear in mind that Rose-breasted Grosbeak is (strangely) encountered more frequently in California from late fall into early spring than is the Black-headed.

The rollicking song of the male sounds much like that of its western replacement, but is slower, a bit lower-pitched, and less apt to consist of the iambic triplets (‘da-da-DAH’) that so characterize the songs of most Black-headed Grosbeaks.  The call-note is a sharp, excited single squeak like that of Black-headed.  Generally, only experienced birders are able to distinguish these species by voice.