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

Aerial Insectivores In Maine

All statesMaine

18 species in this guild. As a group they are -74%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 74% since 1968.

Aerial Insectivores In Maine Population Forecast

If the recent trend holds, Aerial insectivores in Maine is projected to fall about 100% by 2029 — from 2.4 in 2024 to a central estimate of 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±87.7%, with 40% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.795% 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 →
±87.7%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 2029 — from 2.4 in 2024 to a central estimate of 0.00 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±87.7%, 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 →
20250.430.002.1
20260.320.002.0
20270.200.001.9
20280.090.001.8
20290.000.001.7

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%
Northern Rough-winged SwallowHirundinidae-92%
Olive-sided FlycatcherTyrannidae-90%
Barn SwallowHirundinidae-90%
Yellow-bellied FlycatcherTyrannidae-89%
Tree SwallowHirundinidae-87%
Eastern Whip-poor-willCaprimulgidae-86%
Willow FlycatcherTyrannidae-80%
Eastern KingbirdTyrannidae-77%
Least FlycatcherTyrannidae-60%
Purple MartinHirundinidae-60%
Chimney SwiftApodidae-56%
Common NighthawkCaprimulgidae-54%
Alder FlycatcherTyrannidae-45%
Eastern Wood-PeweeTyrannidae-38%
Eastern PhoebeTyrannidae+101%
Great Crested FlycatcherTyrannidae+136%

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