WatchList Species Account for Brewer’s Sparrow (Spizella brewerii)

Qualifies for the list as a Declining Yellow List Species

Photo: © Ashok Khosla

In the sagebrush shrublands of the Intermountain West, the Brewer’s Sparrow is the most abundant breeding bird. Through the mid-1970s, it is estimated that 10% of native sagebrush shrublands were converted to agriculture and grazing. Invasion of exotic plants has contributed to the decline of this habitat type, especially cheatgrass, which now occupies millions of acres of rangeland in the West, and has greatly increased the fire frequency. The loss, degradation and fragmentation of this habitat has been accompanied by a decline in the numbers of the Brewer’s Sparrow; Breeding Bird Surveys indicate yearly declines between 3-6% from 1966-1996. Current thought is that factors operating on the wintering grounds may play a role in regulating population size, but this needs further research. A subspecies, the Timberline Sparrow, may eventually be elevated to full species status; it breeds in western Canada north to Alaska.