Habitat
Virginia's Warblers breed in open pinyon-juniper and oak woodlands often on steep slopes with shrubby ravines throughout most of their range. They also use dense thickets of mountain mahogany in southern Idaho and mixed-evergreen forests on the Mogollon Rim in Arizona. During migration, they tend to gravitate toward pine forests and scrubby or wooded areas adjacent to creeks. On the wintering grounds in Mexico they stick to thorn scrub and tropical deciduous forests.
Back to topFood
Virginia's Warblers pick insects from deciduous vegetation such as oaks, bigtooth maple, and New Mexico locust. Their diet consists primarily of caterpillars, spiders, ants, weevils, stinkbugs, and flying insects, but they may take nectar from flowering plants on occasion.
Back to topNesting
Nest Placement
Males and females inspect potential nest sites together. They typically select a spot on the ground beneath a root or rock, or at the base of clumps of grass, oaks, or New Mexico locusts to provide concealment. They frequently nest on a steep slope, placing the nest on the downslope side of a clump of vegetation.
Nest Description
The female collects grasses and other plant material from the ground to build a cup-shaped nest that she lines with fine grasses and hairs.
Nesting Facts
Clutch Size: | 3-5 eggs |
Number of Broods: | 1 brood |
Egg Length: | 0.6-0.7 in (1.5-1.7 cm) |
Egg Width: | 0.5-0.5 in (1.2-1.3 cm) |
Incubation Period: | 11-14 days |
Nestling Period: | 10-14 days |
Egg Description: | Cream-colored with tiny brown spots. |
Condition at Hatching: | Mostly naked with a bit of grayish down along the back and head. |
Behavior
Virginia's Warblers tend to forage in the middle levels of pinyon-juniper forests and nest on the ground. They frequently wag their tails up and down as they hop from twig to twig looking for insects. Males defend their breeding territories with song, singing from an exposed branch at the top of a tree or shrub. Most individuals likely form monogamous bonds for a single breeding season only, but some males may mate with a second female in the same season. Virginia's Warblers tend to occur in pairs on the breeding grounds, but form mixed-species flocks with other warblers such as Orange-crowned and Black-throated Gray Warblers during migration and on the wintering grounds.
Back to topConservation
Virginia's Warblers are uncommon, and their numbers declined by approximately 1.1% per year for a cumulative decline of about 46% between 1968 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 900,000 Virginia’s Warblers and rates them 15 out of 20 on the Continental Concern Score. They are included in the Yellow Watch List for birds most at risk of extinction without significant conservation actions to reverse declines and reduce threats. Partners in Flight estimates that if current rates of decline continue, Virginia's Warblers will lose another half of their remaining population within the next 61 years. The causes for decline in Virginia's Warblers are not well understood. In some areas, forest management techniques such as controlled burning can reduce available breeding habitat. In other areas, Virginia's Warblers nests are frequently parasitized by Brown-headed Cowbirds, preventing the warblers from raising offspring of their own. Climate change may also affect these birds as they frequently associate with wet drainages, which may shrink as climate warms.
Back to topCredits
Dunne, P. (2006). Pete Dunne's essential field guide companion. Houghton Mifflin Harcourt, New York, USA.
Olson, Christopher R. and Thomas E. Martin. (1999). Virginia's Warbler (Oreothlypis virginiae), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Rosenberg, K. V., J. A. Kennedy, R. Dettmers, R. P. Ford, D. Reynolds, J. D. Alexander, C. J. Beardmore, P. J. Blancher, R. E. Bogart, G. S. Butcher, A. F. Camfield, A. Couturier, D. W. Demarest, W. E. Easton, J. J. Giocomo, R. H. Keller, A. E. Mini, A. O. Panjabi, D. N. Pashley, T. D. Rich, J. M. Ruth, H. Stabins, J. Stanton, and T. Will (2016). Partners in Flight Landbird Conservation Plan: 2016 Revision for Canada and Continental United States. Partners in Flight Science Committee.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
Stephenson, T. and S. Whittle (2013). The Warbler Guide. Princeton University Press, New Jersey, USA.