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

Warbling Vireo Population Trend in Maine

All statesForest birds

Warbling Vireo in Maine has surged: up 133% on the route-weighted index since 1969.

+133%Since 1969TrendPercent 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 →
65Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Warbling Vireo 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 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 →

Warbling Vireo has surged in Maine: up 133% on the route-weighted index since 1969.

Warbling Vireo Population Forecast in Maine

If the recent trend holds, Warbling Vireo in Maine is projected to rise about 15% by 2029 — from 0.95 in 2024 to a central estimate of 1.1 (95% range 0.11–2.1). A 5-year backtest shows a typical error of ±98.9%, with 100% of held-out values landing inside the 95% band.

+15%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 →
1.1Projected 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 →
0.11–2.195% 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 →
±98.9%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, Warbling Vireo in Maine is projected to rise about 15% by 2029 — from 0.95 in 2024 to a central estimate of 1.1 (95% range 0.11–2.1). A 5-year backtest shows a typical error of ±98.9%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20251.10.122.1
20261.10.122.1
20271.10.112.1
20281.10.112.1
20291.10.112.1

Warbling Vireo Survey Routes in Maine

Routes recording Warbling Vireo 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 →
Otisfield Gr1120151977
Seboomook Lk1120101998
Turner820101972
Stacyville520232021
Harmony420241971
Carrying Pl420151980
Medway420181979
Hartford320241975
Manchester319951971
East Troy319961981
Warren319901977
Northfield319781976
Washburn320051979
Ft Fairfield320051994
Lake Moxie320102006
Rome320241996
Newcastle220231971
South Arm220081985
Bowdoin Ctr220111980
Hermon220141967
Cooper219801978
Moose River220081988
Charleston220171980
Benedicta220221978
Cornville220242012

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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