 |
  |
September 1998, Volume 32, Number 1
A Message from the President Newsletter Survey Results Know Your White-crowned Sparrow Zonotrichia leucophrys Pee Wee Audubon: Revels with Reptiles |
Know Your White-crowned Sparrow Zonotrichia leucophrysby Betty Burridge
The adult white-crowns are readily identifiable, and to us, the males and females look alike. Accompanying the adults will be the summer's crop of youngsters. More drably colored, with head stripes of dull buff and brown, the young white-crowns are easily confused with the closely-related Golden-crowned Sparrow, which also winters here. There are two fairly reliable ways of telling the two species apart at all ages: bill color and crown feathering. The bill of the White-crowned Sparrow is always either yellow or pink, while golden-crowned bills are always dusky on top. And the golden-crown always has at least a touch of yellow on the crown between the eyes, while the crown of the young white-crown is buff, turning to brilliant white in adulthood. In spite of these field marks, however, even experienced birders sometimes have difficulty telling one species from the other. The male White-crowned Sparrow is famous for having a song with geographically distinct dialects. The song apparently is learned by the young bird from adult males on his natal territory. The females do not normally sing. Another similar and related species is the less common White-throated Sparrow, which as an adult can have either tan and brown or white and black head stripes. The white-throat, however, has a yellow lore mark just in front of the eye, and an immaculate white throat lightly outlined in black. The white-crown does have a throat patch, but it is pale gray and poorly defined compared to that of the white-throat. Rarely, a winter flock of "crowned sparrows," as some birders call members of the genus Zonotrichia, can contain still another member of the genus. This is the Harris Sparrow, which usually is reported less than once a year in Sonoma County. In winter a Harris Sparrow may look more like a House Sparrow than like any of the other "crowns." Check your field guide for specifics. The White-crowned Sparrow is divided into several races, at least two of which were formerly listed as separate species. Mercifully, all have since been "lumped" together as one species. It is not always easy to separate the races in the field, and in the winter several races may mingle together on their wintering grounds, which range from northern California to central Mexico. Along the coast, Sonoma County has an interesting non-migratory population of White-crowned Sparrows. These are birds of the Nuttall's race, which was formerly listed as a separate species. Most Nuttall's white-crowns live their whole lives within or very near the territory in which they were born, and they are never found more than a couple of miles from the ocean or large estuaries. A bird of this race has a yellow bill, brown back with black stripes, and a white eye-brow beginning at the base of the upper mandible. It is overall a dingier-looking bird than the races that only winter here. Its range extends along much of the western coast of the United States; the Sonoma County Breeding Bird Atlas shows breeding records for the Nuttall's white-crown all along the Sonoma County coast. References: Stallcup, R., 1992, "Sparrows in Winter", PRBO Observer, 94 8-9. Burridge, B., 1995, Sonoma County Breeding Bird Atlas, Madrone Audubon Society |
By the end of September, little brown birds with heads smartly marked
in bold strokes of black and white will again be hopping around the back
yards of Sonoma County. These are our winter resident adult White-crowned
Sparrows, returned from their breeding grounds up north or at higher altitudes.
Once they are back, we can expect them to stay around through the month
of April.Back to the home page.
Calendar | Newsletter | Alerts | Birding | How to Join | Contacting Us | Some of Our Friends
(c) Copyright 1998 Madrone Audubon Society, Inc. All rights reserved.