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Species · Delaware · BBS 2026 Release · 1966–2025

Great Crested Flycatcher Population Trend in Delaware

All statesAerial insectivores

Great Crested Flycatcher in Delaware has surged: up 180% on the route-weighted index since 1968.

+180%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 →
59YearsYears 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 Crested Flycatcher 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 Crested Flycatcher has surged in Delaware: up 180% on the route-weighted index since 1968.

Great Crested Flycatcher Population Forecast in Delaware

If the recent trend holds, Great Crested Flycatcher in Delaware is projected to fall about 24% by 2030 — from 13 in 2025 to a central estimate of 10 (95% range 6.5–14). A 5-year backtest shows a typical error of ±26.1%, with 60% of held-out values landing inside the 95% band.

-24%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 →
10Projected 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 →
6.5–1495% 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 →
±26.1%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 Crested Flycatcher in Delaware is projected to fall about 24% by 2030 — from 13 in 2025 to a central estimate of 10 (95% range 6.5–14). A 5-year backtest shows a typical error of ±26.1%, with 60% 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 →
20269.56.013
20279.66.113
20289.76.313
20299.96.413
2030106.514

Great Crested Flycatcher Survey Routes in Delaware

Routes recording Great Crested Flycatcher 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 →
Pepperbox 22720252017
Harrington2520251966
Pepperbox1620161998
Frederica920251966
Millsboro920252017
Milton 2820252017
Holleyville 2720242006
Holleyville620041966
Milton620161966
Mt Pleasant420191966
Frankford420121966
Lowes Xrds419911966
Wilmington320141967
Georgetown320221992
Dover219871966
Bethany Bch119901966
Blackbird120251994

Great Crested Flycatcher Population Trend in Other States

alabamaarkansascoloradoconnecticutfloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsin

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