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

Aerial Insectivores In Washington

All statesWashington

22 species in this guild. As a group they are -43%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 1970.

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 declined in Washington, down 43% since 1970.

Aerial Insectivores In Washington Population Forecast

If the recent trend holds, Aerial insectivores in Washington is projected to stay roughly flat through 2029, near 4.1 (95% range 2.7–5.5). A 5-year backtest shows a typical error of ±13%, with 100% of held-out values landing inside the 95% band.

+4%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 →
4.1Projected 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 →
2.7–5.595% 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 →
±13%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 Washington is projected to stay roughly flat through 2029, near 4.1 (95% range 2.7–5.5). A 5-year backtest shows a typical error of ±13%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20254.22.85.7
20264.22.85.7
20274.22.75.6
20284.12.75.6
20294.12.75.5

Member Species In Washington

Aerial insectivores species in Washington.
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 →
Black SwiftApodidae-92%
Common PoorwillCaprimulgidae-72%
Bank SwallowHirundinidae-69%
Willow FlycatcherTyrannidae-65%
Olive-sided FlycatcherTyrannidae-59%
Eastern KingbirdTyrannidae-45%
Barn SwallowHirundinidae-37%
Least FlycatcherTyrannidae-37%
Cliff SwallowHirundinidae-28%
Western KingbirdTyrannidae-20%
Violet-green SwallowHirundinidae-16%
Northern Rough-winged SwallowHirundinidae-9%
Western Wood-PeweeTyrannidae-7%
Tree SwallowHirundinidae-7%
Vaux's SwiftApodidae+53%
White-throated SwiftApodidae+62%
Purple MartinHirundinidae+74%
Common NighthawkCaprimulgidae+101%
Hammond's FlycatcherTyrannidae+152%
Say's PhoebeTyrannidae+168%
Dusky FlycatcherTyrannidae+216%
Gray FlycatcherTyrannidae+451%

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