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

Eastern Phoebe Population Trend in Delaware

All statesAerial insectivores

Eastern Phoebe in Delaware has fallen sharply: down 61% on the route-weighted index since 1968.

-61%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 →
17Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Eastern Phoebe 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 declinecomputed 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 →

Eastern Phoebe has fallen sharply in Delaware: down 61% on the route-weighted index since 1968.

Eastern Phoebe Population Forecast in Delaware

If the recent trend holds, Eastern Phoebe in Delaware is projected to rise about 84% by 2029 — from 0.40 in 2024 to a central estimate of 0.73 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±62.8%, with 100% of held-out values landing inside the 95% band.

+84%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 →
0.73Projected 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 →
±62.8%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, Eastern Phoebe in Delaware is projected to rise about 84% by 2029 — from 0.40 in 2024 to a central estimate of 0.73 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±62.8%, 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 →
20250.780.001.8
20260.770.001.8
20270.760.001.7
20280.750.001.7
20290.730.001.7

Eastern Phoebe Survey Routes in Delaware

Routes recording Eastern Phoebe 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 →
Lowes Xrds319911967
Wilmington220131970
Frankford220081966
Holleyville220041967
Milton220151966
Millsboro220232017
Pepperbox 2220242017
Mt Pleasant120191968
Harrington120231966
Frederica120141966
Dover119851972
Bethany Bch119661966
Blackbird120211995
Holleyville 2120162006
Pepperbox120162002
Georgetown120221992
Milton 2120172017

Eastern Phoebe Population Trend in Other States

alabamaarkansascoloradoconnecticutfloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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