BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Virginia's Warbler

ParulidaeForest birdsLeiothlypis virginiae

Virginia's Warbler has surged: up 444% on the route-weighted index since 1970.

+444%Since 1970TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
164RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Virginia's Warbler

The Virginia's Warbler (Leiothlypis virginiae) is a North American member of the Wood-Warblers (Parulidae). In this analysis it is grouped with the forest birds.

Size
4.5–5.5 in long (11–14 cm) — a small, active songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 164 Breeding Bird Survey routes across 9 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Parulidae · Forest birds

Notable Virginia's Warbler TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Virginia's Warbler. See the full index history below.

Virginia's Warbler Population Forecast

If the recent trend holds, Virginia's Warbler is projected to rise about 23% by 2029 — from 0.12 in 2024 to a central estimate of 0.15 (95% range 0.09–0.21). A 5-year backtest shows a typical error of ±59.9%, with 60% of held-out values landing inside the 95% band.

+23%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.15Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.09–0.2195% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±59.9%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Virginia's Warbler is projected to rise about 23% by 2029 — from 0.12 in 2024 to a central estimate of 0.15 (95% range 0.09–0.21). A 5-year backtest shows a typical error of ±59.9%, with 60% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.140.090.20
20260.150.090.20
20270.150.090.20
20280.150.090.21
20290.150.090.21

Where the Virginia's Warbler Is Detected

BBS routes recording Virginia's Warbler, sized by most recent count.

Virginia's Warbler Population Trend by State

Virginia's Warbler population trend by state.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+109%197024
Californiainsufficient datan/a1
Colorado+321%197365
Idahoinsufficient datan/a2
Nevada+135%20055
New Mexico+45%197023
South Dakotainsufficient datan/a1
Utah-78%198840
Wyominginsufficient datan/a3

Virginia's Warbler Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Virginia's Warbler population trend by Bird Conservation Region.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Great Basin+33%198912
Southern Rockies / Colorado Plateau+114%1970120
Sierra Madre Occidental+27%197022
Chihuahuan Desert-82%19803

Virginia's Warbler Conservation Status

Our route-weighted index shows it up about 444% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.