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

Eastern Bluebird Population Trend in New Jersey

All statesForest birds

Eastern Bluebird in New Jersey has surged: up 615% on the route-weighted index since 1968.

+615%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 →
36Routes 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 →
53YearsYears 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 Bluebird 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 →

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 →

Eastern Bluebird has surged in New Jersey: up 615% on the route-weighted index since 1968.

Eastern Bluebird Population Forecast in New Jersey

If the recent trend holds, Eastern Bluebird in New Jersey is projected to fall about 33% by 2029 — from 4.0 in 2024 to a central estimate of 2.7 (95% range 1.6–3.8). A 5-year backtest shows a typical error of ±36%, with 60% of held-out values landing inside the 95% band.

-33%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 →
2.7Projected 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 →
1.6–3.895% 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 →
±36%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 Bluebird in New Jersey is projected to fall about 33% by 2029 — from 4.0 in 2024 to a central estimate of 2.7 (95% range 1.6–3.8). A 5-year backtest shows a typical error of ±36%, 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 →
20252.51.43.6
20262.61.53.7
20272.61.53.7
20282.71.63.8
20292.71.63.8

Eastern Bluebird Survey Routes in New Jersey

Routes recording Eastern Bluebird 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 →
Greenwich920241988
High Point920241977
Ramseysburg920241995
Dover720221994
Pottersville720241989
Cape May Ch720131993
Croton 2720242008
Woodbury Hgt620241989
Pomona620241982
Friendship520241977
Pedricktown 2520242014
Spraguetown 3520242023
Hope419931988
Winslow420241989
Sandbrook320241988
Croton320071982
Gillette320241989
Six Points220231996
Del Haven219911991
Toms River220241966
New Bedford220241986
Kemah Lake220241966
Keyport220172008
Cranbury220232001
Estell Manor220222022

Eastern Bluebird Population Trend in Other States

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

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