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

Black-and-white Warbler Population Trend in New Jersey

All statesForest birds

Black-and-white Warbler in New Jersey has increased: up 46% on the route-weighted index since 1968.

+46%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 →
35Routes 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 Black-and-white 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 →

No notable trend signals for Black-and-white Warbler in New Jersey. See the full index history below.

Black-and-white Warbler Population Forecast in New Jersey

If the recent trend holds, Black-and-white Warbler in New Jersey is projected to fall about 69% by 2029 — from 2.6 in 2024 to a central estimate of 0.80 (95% range 0.00–3.0). A 5-year backtest shows a typical error of ±59.2%, 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 →
0.80Projected 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 →
0.00–3.095% 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 →
±59.2%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, Black-and-white Warbler in New Jersey is projected to fall about 69% by 2029 — from 2.6 in 2024 to a central estimate of 0.80 (95% range 0.00–3.0). A 5-year backtest shows a typical error of ±59.2%, 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 →
20250.860.003.1
20260.840.003.1
20270.830.003.1
20280.810.003.0
20290.800.003.0

Black-and-white Warbler Survey Routes in New Jersey

Routes recording Black-and-white 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 32120242023
Toms River1020241966
Pomona1020241978
Friendship620241977
Villas519811979
Estell Manor420222021
Spraguetown 2320072000
Bennett Mill320001966
Cape May Ch320111992
Winslow320241989
Holmansville220041969
Hope219941975
High Point220241977
Pottersville219971979
Woodbury Hgt120141991
Greenwich120151973
Six Points119861978
Albion120051966
Ancora119721967
Sandbrook120091980
New Bedford120101993
Croton120071978
Midvale120031971
Kemah Lake120241981
Bloomsbury120101969

Black-and-white Warbler Population Trend in Other States

alabamaarkansascaliforniaconnecticutdelawaregeorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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