BirdAnalyst
Species · Delaware · BBS 2025 Release · 1966–2024

Great Egret Population Trend in Delaware

All statesWetland birds

Great Egret in Delaware has surged: up 404% on the route-weighted index since 1968.

+404%Since 1968TrendPercent 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 →
12Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Egret Trends in DelawareNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed 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 →

Great Egret has surged in Delaware: up 404% on the route-weighted index since 1968.

Great Egret Population Forecast in Delaware

If the recent trend holds, Great Egret in Delaware is projected to rise about 32% by 2029 — from 5.8 in 2024 to a central estimate of 7.7 (95% range 1.1–14). A 5-year backtest shows a typical error of ±70.6%, with 100% of held-out values landing inside the 95% band.

+32%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 →
7.7Projected 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 →
1.1–1495% 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 →
±70.6%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, Great Egret in Delaware is projected to rise about 32% by 2029 — from 5.8 in 2024 to a central estimate of 7.7 (95% range 1.1–14). A 5-year backtest shows a typical error of ±70.6%, with 100% 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 →
20257.20.5914
20267.30.7114
20277.40.8414
20287.50.9614
20297.71.114

Great Egret Survey Routes in Delaware

Routes recording Great Egret in Delaware.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Blackbird2420241994
Frankford1519661966
Bethany Bch519901967
Pepperbox520161998
Pepperbox 2320242017
Mt Pleasant220181974
Wilmington220141968
Harrington220241967
Lowes Xrds219911975
Dover119851972
Holleyville119981998
Georgetown120182000

Great Egret Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutfloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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