White-crowned Sparrow    Zonotrichia leucophrys

Migratory Status: Short-distance migrant

PIF Population Estimate: 72 000 000

Percent of western hemisphere population breeding in boreal forest: 48%

BAM Effective Detection Radius (m) : 99.47

PIF Maximum Detection Distance (m) : 200

Canadian BBS Population trend: 0.9 n.s. (-2.2 to 4.0)

Life History

Its wide distribution, high abundance, and conspicuous nature have made the White-crowned Sparrow one of the most studied passerine species in North America. It has been a popular subject in studies of the development and geographic variation of bird song, basic physiology, breeding ecology, and population biology.

The isolation of certain sub-populations during relatively recent glacial periods has resulted in some morphological differences. As a result, four subspecies (Z. l. leucophrys, Z. l. gambelii, Z. l. pugetensis, and Z. l. nuttalli) have been recognized, based largely on differences in body size, bill colour, and the colour of the lores (area of feathering just above the eye).

The breeding range includes most of the forested and non-forested areas in the northern portion of the continent, from western Alaska, east to northwestern Newfoundland. Migratory populations also exist throughout the northern Rocky Mountains, though resident populations occupy most of the mountainous areas of the northwest United States. Of the recognized subspecies, boreal breeding birds are either the Z. l. leucophrys subspecies (east of Hudson Bay and the southern Rocky Mountains) or Z. l. gambelii (west of Hudson Bay). Some individuals winter casually in coastal Alaska, British Columbia’s lower mainland, and in southern Ontario. Most birds, however, winter south of the border throughout the 48 United States and into northern Mexico.

Reference(s)

Chilton, G., M. C. Baker, C. D. Barrentine, and M. A. Cunningham. 1995. White-crowned Sparrow (Zonotrichia leucophrys), 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/183