BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

Blue Jay Population Trend in New Jersey

All statesGeneralists

Blue Jay in New Jersey has declined: down 47% on the route-weighted index since 1968.

-47%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 →
44Routes 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 Blue Jay Trends in New JerseyNotable 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 New Jersey. See the full index history below.

Blue Jay Population Forecast in New Jersey

If the recent trend holds, Blue Jay in New Jersey is projected to fall about 35% by 2029 — from 15 in 2024 to a central estimate of 9.6 (95% range 3.9–15). A 5-year backtest shows a typical error of ±27.6%, with 60% of held-out values landing inside the 95% band.

-35%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 →
9.6Projected 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 →
3.9–1595% 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 →
±27.6%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, Blue Jay in New Jersey is projected to fall about 35% by 2029 — from 15 in 2024 to a central estimate of 9.6 (95% range 3.9–15). A 5-year backtest shows a typical error of ±27.6%, with 60% 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 →
2025104.616
2026104.416
202710.04.216
20289.84.016
20299.63.915

Blue Jay Survey Routes in New Jersey

Routes recording Blue Jay in New Jersey.
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 →
Croton 24620242008
Holmansville3220091969
Dover3120231977
Woodbury Hgt3020241967
Midvale2920221967
Kemah Lake2720241966
Passaic2619691969
Villas2619811979
Cape May Ch2320131992
Ancora2219771966
Pedricktown 22220242013
Sandbrook2120241969
New Bedford2120241969
Masonville2019701966
Mt Misery2019891976
Del Haven1919911991
Ramseysburg1920241995
Gillette1720241988
Keyport1720221986
Six Points1620241978
Greenwich1420241966
Clarksville1419911969
Winslow1320241989
Cranbury1220241987
Toms River1120241966

Blue Jay Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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