BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Orange-crowned Warbler Population Analysis

ParulidaeForest birdsLeiothlypis celata

Orange-crowned Warbler has surged: up 259% on the route-weighted index since 1970.

+259%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 →
726RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57Years 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 Orange-crowned Warbler

The Orange-crowned Warbler (Leiothlypis celata) 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 726 Breeding Bird Survey routes across 13 states, most concentrated in the Northern Pacific Rainforest.
Family
Parulidae · Forest birds

Notable Orange-crowned 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Orange-crowned Warbler has surged in surveyed states: up 259% on the route-weighted index since 1970.

Orange-crowned Warbler Population Forecast

If the recent trend holds, Orange-crowned Warbler is projected to rise about 83% by 2030 — from 0.69 in 2025 to a central estimate of 1.3 (95% range 0.84–1.7). A 5-year backtest shows a typical error of ±62.9%, with 0% of held-out values landing inside the 95% band.

+83%Change by 2030TrendPercent 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 →
1.3Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.84–1.795% 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 →
±62.9%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, Orange-crowned Warbler is projected to rise about 83% by 2030 — from 0.69 in 2025 to a central estimate of 1.3 (95% range 0.84–1.7). A 5-year backtest shows a typical error of ±62.9%, with 0% of held-out values landing inside the 95% band.19682030
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 →
20261.20.791.6
20271.20.801.7
20281.20.811.7
20291.30.821.7
20301.30.841.7

Where the Orange-crowned Warbler Is Detected

BBS routes recording Orange-crowned Warbler, sized by most recent count.

Orange-crowned Warbler Population Trend by State

Orange-crowned 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 →
Alaska+294%1973123
Arizona-83%19828
California+24%1970176
Colorado+532%197369
Idaho+204%197336
Montana+55%197040
Nevada+55%199711
New Mexico-30%197713
North Dakotainsufficient datan/a1
Oregon-70%197096
Utah-49%197847
Washington-59%197083
Wyoming-36%197423

Orange-crowned Warbler Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Orange-crowned 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 →
BCR 2-39%198520
BCR 4+54%197868
Northern Pacific Rainforest-16%1970159
Great Basin-27%197099
Northern Rockies+186%1970125
Sierra Nevada-23%197334
Southern Rockies / Colorado Plateau13×1972117
Coastal California+143%197087
Sierra Madre Occidental-87%19828

Orange-crowned Warbler Conservation Status

Our route-weighted index shows it up about 259% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.