BirdAnalyst
Species · Maine · BBS 2025 Release · 1966–2024

Yellow Warbler Population Trend in Maine

All statesForest birds

Yellow Warbler in Maine has declined: down 42% on the route-weighted index since 1968.

-42%Since 1968TrendPercent 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 →
72Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow Warbler Trends in MaineNotable 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 Yellow Warbler in Maine. See the full index history below.

Yellow Warbler Population Forecast in Maine

If the recent trend holds, Yellow Warbler in Maine is projected to fall about 43% by 2029 — from 4.0 in 2024 to a central estimate of 2.3 (95% range 0.00–7.0). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.

-43%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 →
2.3Projected 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 →
0.00–7.095% 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 →
±43.4%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, Yellow Warbler in Maine is projected to fall about 43% by 2029 — from 4.0 in 2024 to a central estimate of 2.3 (95% range 0.00–7.0). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20252.70.007.4
20262.60.007.3
20272.50.007.2
20282.40.007.1
20292.30.007.0

Yellow Warbler Survey Routes in Maine

Routes recording Yellow Warbler in Maine.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Washburn4020051979
St David4020051982
Ft Fairfield3020051993
Benton2419801972
Warren1919901973
Hermon1820191966
East Troy1520191972
Cornville1520242012
Turner 21520242011
Manchester1319951971
Charleston1320191975
Newcastle1120241971
Jefferson1020101991
Harmony920241967
Brooks920191977
Turner820101972
Boundary720161993
Otisfield Gr620151966
Benedicta620191976
Ludlow619981968
Biddeford520181973
Kittery Pt520241966
Freedom520221973
Baker Lake520051998
Hartford420241975

Yellow Warbler Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.