Associated Species: Other species that may use habitat in a similar way and/or respond similarly to threats, management, and conservation activities include Broad-tailed Hummingbird and Green-tailed Towhee.

Distribution: Virginia's Warblers breed throughout Utah and Arizona, in eastern Nevada, western New Mexico, and from the Front Range westward in Colorado. They breed in suitable habitat throughout Physiographic Area 87 in Colorado. They winter in western and central Mexico.

Habitat Requirements: Virginia's Warblers nest in dense mountain shrublands, especially Gambel oak, and in ponderosa pine and pinyon-juniper woodlands with a shrubby understory.

Ecology: Spring migrants arrive in Colorado in late April, but nesting may not begin until late May. Young may still be in nests in August, indicating either very late nesting or a second brood. Most birds have left the state by the end of September.

Management Issues and Conservation Recommendations: Management of large acreages of mountain shrubland in young growth stages for deer and elk does not benefit Virginia's Warblers, which require larger shrubs, especially Gambel oak. Large-diameter Gambel oaks, which produce acorns for deer, bears, Wild Turkeys, and Band-tailed Pigeons and which provide shade and access to elk sedge understory production for cattle and elk, benefit Virginia's Warblers as well. Manage for mature and old-growth Gambel oak stands.

Virginia's Warblers may be subject to high rates of Brown-headed Cowbird nest parasitism in some areas; cowbirds are often found in association with livestock. Rest large mountain shrubland pastures in rotation to allow relief from cowbird parasitism.

Status and Reasons for Concern: This species is on the national Watch List, indicating a high conservation need throughout its range. A very high proportion (estimated at 42%) of this species' total population occurs within Physiographic Area 87, indicating that this area has high responsibility for the conservation of Virginia's Warblers. This species is not adequately monitored by the BBS within Physiographic Area 87, and data collected between 1969 and 1996 are too sparse to allow analysis of trend data (n = 9 routes). However, BBS data for the period 1966-1996 approach a statistically significant, survey-wide annual rate of increase (P = 0.11; n = 44 routes). Virginia's Warblers were present on an average of 51.97% (SE = 2.61) of the BBS routes run in Physiographic Area 87 in Colorado during 1988-1997, at an average abundance of 3.44 (SE = 0.38) individuals per route. The mean number of routes run each year was 11.4 (SE = 1.55). This species is monitored by MCB with point transects.

Biological Objective: Maintain or increase the species' distribution and abundance, as based upon results of the BBS and MCB monitoring programs.

Selected References: Andrews and Righter 1992, Kingery 1998, Martin 1998.