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

Prairie Warbler Population Trend in New Jersey

All statesForest birds

Prairie Warbler in New Jersey has fallen sharply: down 58% on the route-weighted index since 1968.

-58%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 →
34Routes 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 Prairie 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 declinecomputed 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 →

Prairie Warbler has fallen sharply in New Jersey: down 58% on the route-weighted index since 1968.

Prairie Warbler Population Forecast in New Jersey

If the recent trend holds, Prairie Warbler in New Jersey is projected to fall about 69% by 2029 — from 2.8 in 2024 to a central estimate of 0.84 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±52.9%, with 100% of held-out values landing inside the 95% band.

-69%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 →
0.84Projected 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 →
0.00–5.395% 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 →
±52.9%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, Prairie Warbler in New Jersey is projected to fall about 69% by 2029 — from 2.8 in 2024 to a central estimate of 0.84 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±52.9%, 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 →
20251.10.005.6
20261.10.005.5
20270.990.005.4
20280.920.005.3
20290.840.005.3

Prairie Warbler Survey Routes in New Jersey

Routes recording Prairie 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 31920242023
Toms River1220241966
Bennett Mill1120001966
Friendship1020241977
Pomona820241978
Estell Manor420222022
Del Haven319911991
Ancora319771966
Holmansville320091969
Pottersville320161979
Winslow320241989
Albion220221966
Sandbrook220241972
Gillette220241989
Bennett Mill 2220222016
Woodbury Hgt119911986
Greenwich120241966
Six Points120241978
Spraguetown 2120122000
New Bedford119981969
Croton119741974
Hope119941977
Midvale120142002
Kemah Lake120221969
Bloomsbury120221990

Prairie Warbler Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamainemarylandmassachusettsmichiganmississippimissourinew-hampshirenew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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