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Species · Maine · BBS 2025 Release · 1966–2024

Tennessee Warbler Population Trend in Maine

All statesForest birds

Tennessee Warbler in Maine has collapsed: down 87% on the route-weighted index since 1971.

-87%Since 1971TrendPercent 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 →
60Routes 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Tennessee 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 →

long arc declinecomputed 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 →

Tennessee Warbler has collapsed in Maine: down 87% on the route-weighted index since 1971.

Tennessee Warbler Population Forecast in Maine

If the recent trend holds, Tennessee Warbler in Maine is projected to fall about 100% by 2027 — from 0.10 in 2022 to a central estimate of 0.00 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±150.3%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2027TrendPercent 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 →
0.00Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.195% 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 →
±150.3%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, Tennessee Warbler in Maine is projected to fall about 100% by 2027 — from 0.10 in 2022 to a central estimate of 0.00 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±150.3%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.000.001.1
20240.000.001.1
20250.000.001.1
20260.000.001.1
20270.000.001.1

Tennessee Warbler Survey Routes in Maine

Routes recording Tennessee 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 →
Northfield1819811976
Winn919971978
Baxter719841977
Seboomook Lk719931978
Waite619771977
Clayton Lake 2420112010
Topsfield319921978
Clayton Lake320081977
Washburn319931990
Otisfield Gr219761976
Manchester219741971
Benton219771971
Carrying Pl219931980
Cambridge219831977
Boundary220042004
Ft Fairfield219981994
St David219921982
Weeks Brook220151997
Baker Lake220041994
Heron Lake219991983
Northfield 2120221992
Westbrook119891987
Biddeford119791978
Kittery Pt119681968
Newcastle119791979

Tennessee Warbler Population Trend in Other States

alaskamichiganminnesotamontananew-hampshirenew-yorkpennsylvaniavermontwisconsin

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