BirdAnalyst
Guild · Maine · BBS 2026 Release · 1966–2025

Aerial Insectivores In Maine

All statesMaine

18 species in this guild. As a group they are -72%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 →

Aerial insectivores as a group have fallen sharply in Maine, down 72% since 1968.

Aerial Insectivores In Maine Population Forecast

If the recent trend holds, Aerial insectivores in Maine is projected to fall about 100% by 2030 — from 2.1 in 2025 to a central estimate of 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±91.4%, with 20% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.795% 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 →
±91.4%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, Aerial insectivores in Maine is projected to fall about 100% by 2030 — from 2.1 in 2025 to a central estimate of 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±91.4%, with 20% of held-out values landing inside the 95% band.19662030
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 →
20260.450.002.2
20270.340.002.1
20280.220.002.0
20290.110.001.9
20300.000.001.7

Member Species In Maine

Aerial insectivores 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 →
Cliff SwallowHirundinidae-95%
Bank SwallowHirundinidae-92%
Barn SwallowHirundinidae-91%
Olive-sided FlycatcherTyrannidae-90%
Yellow-bellied FlycatcherTyrannidae-89%
Tree SwallowHirundinidae-89%
Northern Rough-winged SwallowHirundinidae-88%
Eastern Whip-poor-willCaprimulgidae-87%
Willow FlycatcherTyrannidae-76%
Eastern KingbirdTyrannidae-72%
Purple MartinHirundinidae-60%
Chimney SwiftApodidae-55%
Common NighthawkCaprimulgidae-54%
Least FlycatcherTyrannidae-49%
Alder FlycatcherTyrannidae-37%
Eastern Wood-PeweeTyrannidae-33%
Eastern PhoebeTyrannidae+108%
Great Crested FlycatcherTyrannidae+149%

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.