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

Wetland Birds In Delaware

All statesDelaware

23 species in this guild. As a group they are +35%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 →

No notable trend signals for wetland birds in Delaware. See the full index history below.

Wetland Birds In Delaware Population Forecast

If the recent trend holds, Wetland birds in Delaware is projected to rise about 23% by 2030 — from 6.1 in 2025 to a central estimate of 7.4 (95% range 3.7–11). A 5-year backtest shows a typical error of ±17.7%, with 80% of held-out values landing inside the 95% band.

+23%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 →
7.4Projected 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 →
3.7–1195% 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 →
±17.7%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, Wetland birds in Delaware is projected to rise about 23% by 2030 — from 6.1 in 2025 to a central estimate of 7.4 (95% range 3.7–11). A 5-year backtest shows a typical error of ±17.7%, with 80% 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 →
20267.33.611
20277.33.611
20287.43.611
20297.43.611
20307.43.711

Member Species In Delaware

Wetland birds species in Delaware.
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 →
Common TernLaridae-90%
Least TernLaridae-85%
Herring GullLaridae-80%
Ring-billed GullLaridae-70%
Great Black-backed GullLaridae-69%
Western Cattle-EgretArdeidae-46%
Red-winged BlackbirdIcteridae-22%
Laughing GullLaridae-5%
Boat-tailed GrackleIcteridae-2%
Belted KingfisherAlcedinidae+4%
Swamp SparrowPasserellidae+7%
Little Blue HeronArdeidae+21%
Glossy IbisThreskiornithidae+28%
Black-crowned Night HeronArdeidae+34%
Green HeronArdeidae+56%
Clapper RailRallidae+141%
Black SkimmerLaridae+184%
Double-crested CormorantPhalacrocoracidae+233%
Great EgretArdeidae+331%
Seaside SparrowPasserellidae+660%
Forster's TernLaridae14×
Snowy EgretArdeidae18×
Great Blue HeronArdeidae32×

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