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

Generalists In Maine

All statesMaine

56 species in this guild. As a group they are -55%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Generalists as a group have fallen sharply in Maine, down 55% since 1968.

Forecast

If the recent trend holds, Generalists in Maine is projected to fall about 64% by 2029 — from 5.0 in 2024 to a central estimate of 1.8 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±56.5%, with 40% of held-out values landing inside the 95% band.

-64%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 →
1.8Projected 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 →
0.00–4.195% 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 →
±56.5%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, Generalists in Maine is projected to fall about 64% by 2029 — from 5.0 in 2024 to a central estimate of 1.8 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±56.5%, with 40% 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 →
20252.20.004.5
20262.10.004.4
20272.00.004.3
20281.90.004.2
20291.80.004.1

Member Species In Maine

Generalists species in Maine.
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 →
Eastern TowheePasserellidae-97%
Rusty BlackbirdIcteridae-88%
European StarlingSturnidae-87%
Field SparrowPasserellidae-87%
Evening GrosbeakFringillidae-86%
Purple FinchFringillidae-84%
Brown ThrasherMimidae-84%
Brown-headed CowbirdIcteridae-81%
American KestrelFalconidae-80%
Lincoln's SparrowPasserellidae-77%
White-throated SparrowPasserellidae-73%
Black-billed CuckooCuculidae-71%
Common GrackleIcteridae-67%
Red-winged BlackbirdIcteridae-66%
Rose-breasted GrosbeakCardinalidae-61%
Northern HarrierAccipitridae-56%
Ruffed GrousePhasianidae-54%
Pine SiskinFringillidae-53%
House SparrowPasseridae-52%
Belted KingfisherAlcedinidae-50%
Canada JayCorvidae-47%
Song SparrowPasserellidae-47%
Northern MockingbirdMimidae-46%
American GoldfinchFringillidae-46%
Baltimore OrioleIcteridae-46%
Great Horned OwlStrigidae-32%
Scarlet TanagerCardinalidae-28%
Common RavenCorvidae-24%
Blue JayCorvidae-21%
Sharp-shinned HawkAccipitridae-20%
Gray CatbirdMimidae-17%
Ruby-throated HummingbirdTrochilidae-15%
Red-shouldered HawkAccipitridae-12%
Fox SparrowPasserellidae+20%
American GoshawkAccipitridae+23%
Cooper's HawkAccipitridae+33%
Barred OwlStrigidae+33%
Swamp SparrowPasserellidae+48%
MerlinFalconidae+50%
Cedar WaxwingBombycillidae+57%
White-winged CrossbillFringillidae+71%
American CrowCorvidae+75%
OspreyPandionidae+80%
Yellow-billed CuckooCuculidae+96%
Chipping SparrowPasserellidae+97%
Broad-winged HawkAccipitridae+134%
Red CrossbillFringillidae+243%
Rock PigeonColumbidae+246%
Indigo BuntingCardinalidae+283%
Red-tailed HawkAccipitridae+500%
House FinchFringillidae+568%
Bald EagleAccipitridae+575%
Turkey VultureCathartidae+632%
Mourning DoveColumbidae21×
Wild TurkeyPhasianidae29×
Northern CardinalCardinalidae49×

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