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

Blue Jay Population Trend in Delaware

All statesForest birds

Blue Jay in Delaware has held roughly steady: down 2% on the route-weighted index since 1968.

-2%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 Blue Jay 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 →

No notable trend signals for Blue Jay in Delaware. See the full index history below.

Blue Jay Population Forecast in Delaware

If the recent trend holds, Blue Jay in Delaware is projected to fall about 13% by 2030 — from 9.0 in 2025 to a central estimate of 7.9 (95% range 2.7–13). A 5-year backtest shows a typical error of ±21.1%, with 100% of held-out values landing inside the 95% band.

-13%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 →
7.9Projected 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 →
2.7–1395% 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 →
±21.1%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, Blue Jay in Delaware is projected to fall about 13% by 2030 — from 9.0 in 2025 to a central estimate of 7.9 (95% range 2.7–13). A 5-year backtest shows a typical error of ±21.1%, with 100% 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 →
20268.23.013
20278.12.913
20288.02.913
20298.02.813
20307.92.713

Blue Jay Survey Routes in Delaware

Routes recording Blue Jay 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 →
Holleyville2720041966
Frederica2320251966
Holleyville 21620242006
Harrington1520251966
Lowes Xrds1319911966
Dover1219871966
Wilmington1120141966
Milton1120161966
Georgetown1120221992
Bethany Bch819901966
Frankford620121966
Pepperbox 2620252017
Blackbird420251994
Mt Pleasant320191966
Millsboro320252017
Pepperbox320161998
Milton 2320252017

Blue Jay Population Trend in Other States

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

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