Species Assessment for Brewer's Sparrow (Spizella Breweri) in Wyoming
Author(s):Publication Date: 2004-09
GARY P. BEAUVAIS
Paula L Hansley
Tags: WLCI, WLCI Agency Report, BLM
The Brewer’s Sparrow (Spizella breweri) has significantly declined throughout its breeding
range in the last 25 years (Ashley and Stoval 2004). Despite being thought of by many as the
most common bird in spring and summer in shrubsteppe habitat, the Brewer’s Sparrow has been
given special conservation status in several western states, including Wyoming (Knick and
Rotenberry 2000). Habitat fragmentation and other processes threaten Brewer’s Sparrow
populations in several ways. In this report, shrubsteppe is defined as habitat with a “…codominance of sagebrush [Artemesia spp.] and native bunch grass and moderate shrub cover” (B.
Walker, personal communication).
This report reviews key published literature, identifies experts and current research on the
Brewer’s Sparrow, and presents existing information on the distribution, biology, ecological niche,
and conservation planning being conducted for this species on state and range-wide scales.
Included is a brief discussion of the controversy of species versus subspecies status and ecological
niche for the subspecies S. b. taverneri (Timberline Sparrow), which breeds at high elevations in
Alaska, Canada, and western Montana and may breed at high elevations in Wyoming (S. Jones,
personal communication). In this assessment, unless specifically noted, the subspecies being
discussed is S. b. breweri.