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

Chimney Swift Population Trend in New Jersey

All statesAerial insectivores

Chimney Swift in New Jersey has held roughly steady: down 6% on the route-weighted index since 1968.

-6%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 →
41Routes 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 Chimney Swift 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 Chimney Swift in New Jersey. See the full index history below.

Chimney Swift Population Forecast in New Jersey

If the recent trend holds, Chimney Swift in New Jersey is projected to stay roughly flat through 2029, near 5.8 (95% range 2.5–9.2). A 5-year backtest shows a typical error of ±19.7%, with 100% of held-out values landing inside the 95% band.

+4%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 →
5.8Projected 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 →
2.5–9.295% 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 →
±19.7%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, Chimney Swift in New Jersey is projected to stay roughly flat through 2029, near 5.8 (95% range 2.5–9.2). A 5-year backtest shows a typical error of ±19.7%, 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 →
20256.02.79.4
20266.02.69.3
20275.92.69.3
20285.92.59.2
20295.82.59.2

Chimney Swift Survey Routes in New Jersey

Routes recording Chimney Swift 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 →
Deepwater4319771969
Hope3919941970
Bloomsbury3820241969
Del Haven3119911991
Midvale2920221967
Pedricktown2720121991
Greenwich1920241966
Cape May Ch1820131992
Bennett Mill 21520242016
Dover1220231977
Croton1120071970
Mt Misery1119881976
Keyport1020221990
Albion820221966
Woodbury Hgt720241967
Pedricktown 2720242013
Sandbrook620241969
Kemah Lake620241966
Pomona520241978
Toms River420241966
Masonville419701966
Holmansville420091969
Clarksville419911969
Cranbury420241987
Villas419811979

Chimney Swift Population Trend in Other States

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

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