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

Qualifies for the list as a Declining Yellow List Species


Photo: © Ashok Khosla
Photo: Greg Lavaty

In the sagebrush shrublands of the Intermountain West, the Brewer’s Sparrow is the most abundant breeding bird. However, the mid-1970s saw an estimated 10% decline of native sagebrush shrublands as it was converted for agriculture and grazing. Invasion of exotic plants, especially cheatgrass, has contributed to the decline of this habitat type, 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.