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

Pine Warbler Population Trend in New Jersey

All statesForest birds

Pine Warbler in New Jersey has surged: up 261% on the route-weighted index since 1968.

+261%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 →
29Routes 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 Pine Warbler 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 →

Pine Warbler has surged in New Jersey: up 261% on the route-weighted index since 1968.

Pine Warbler Population Forecast in New Jersey

If the recent trend holds, Pine Warbler in New Jersey is projected to fall about 26% by 2029 — from 10 in 2024 to a central estimate of 7.5 (95% range 0.16–15). A 5-year backtest shows a typical error of ±28.5%, with 80% of held-out values landing inside the 95% band.

-26%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 →
7.5Projected 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 →
0.16–1595% 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 →
±28.5%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, Pine Warbler in New Jersey is projected to fall about 26% by 2029 — from 10 in 2024 to a central estimate of 7.5 (95% range 0.16–15). A 5-year backtest shows a typical error of ±28.5%, with 80% 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 →
20257.30.0015
20267.40.0015
20277.40.0515
20287.50.1115
20297.50.1615

Pine Warbler Survey Routes in New Jersey

Routes recording Pine Warbler 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 →
Spraguetown 37520242021
Friendship4820241977
Pomona4620241978
Winslow2520241989
Estell Manor2220222021
Bennett Mill1420001966
Del Haven1219911991
Spraguetown 21220122000
Villas1219811979
Toms River1020241966
Spraguetown919991977
Cape May Ch920131992
Holmansville820091969
Bennett Mill 2620242016
Albion520221967
Mt Misery319891976
Woodbury Hgt220061988
New Bedford220171969
Midvale220141977
Kemah Lake220172005
Dover220221992
Greenwich120241982
Six Points120241978
Ancora119771966
Sandbrook120212013

Pine Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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