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

Bald Eagle Population Trend in Delaware

All statesGeneralists

Bald Eagle in Delaware has surged: up 34× on the route-weighted index since 1997.

34×Since 1997TrendPercent 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 →
28YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bald Eagle 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 →

Bald Eagle has surged in Delaware: up 34× on the route-weighted index since 1997.

Bald Eagle Population Forecast in Delaware

If the recent trend holds, Bald Eagle in Delaware is projected to fall about 21% by 2029 — from 4.4 in 2024 to a central estimate of 3.5 (95% range 2.0–4.9). A 5-year backtest shows a typical error of ±51.6%, with 0% of held-out values landing inside the 95% band.

-21%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 →
3.5Projected 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 →
2.0–4.995% 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 →
±51.6%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, Bald Eagle in Delaware is projected to fall about 21% by 2029 — from 4.4 in 2024 to a central estimate of 3.5 (95% range 2.0–4.9). A 5-year backtest shows a typical error of ±51.6%, with 0% of held-out values landing inside the 95% band.19922029
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 →
20253.01.54.4
20263.11.74.6
20273.21.84.7
20283.31.94.8
20293.52.04.9

Bald Eagle Survey Routes in Delaware

Routes recording Bald Eagle 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 →
Harrington520241992
Millsboro520242017
Holleyville 2520242009
Pepperbox 2520242017
Frankford420122007
Mt Pleasant220182006
Blackbird220241996
Wilmington120042004
Milton120142006
Pepperbox120162000
Georgetown120212016
Milton 2120172017

Bald Eagle Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutfloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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