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

Yellow Warbler Population Trend in New Jersey

All statesForest birds

Yellow Warbler in New Jersey has surged: up 121% on the route-weighted index since 1968.

+121%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 →
38Routes 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 Yellow 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 →

Yellow Warbler has surged in New Jersey: up 121% on the route-weighted index since 1968.

Yellow Warbler Population Forecast in New Jersey

If the recent trend holds, Yellow Warbler in New Jersey is projected to rise about 108% by 2029 — from 2.1 in 2024 to a central estimate of 4.5 (95% range 1.2–7.7). A 5-year backtest shows a typical error of ±101.5%, with 100% of held-out values landing inside the 95% band.

+108%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 →
4.5Projected 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 →
1.2–7.795% 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 →
±101.5%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, Yellow Warbler in New Jersey is projected to rise about 108% by 2029 — from 2.1 in 2024 to a central estimate of 4.5 (95% range 1.2–7.7). A 5-year backtest shows a typical error of ±101.5%, 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 →
20254.41.27.7
20264.41.27.7
20274.51.27.7
20284.51.27.7
20294.51.27.7

Yellow Warbler Survey Routes in New Jersey

Routes recording Yellow 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 →
High Point1820241977
Croton1320071970
Hope1319941970
Dover1020231977
Bloomsbury620241969
Gillette620241988
Ramseysburg620241995
Toms River420241966
Clarksville419911969
Robbinsville419791966
Holmansville319961969
Croton 2320232009
Greenwich220181966
Deepwater219771971
Del Haven219911991
Midvale220191967
Kemah Lake220241966
Friendship219961992
Villas219791979
Mt Misery219891976
Woodbury Hgt120161968
Six Points120231981
Albion120211971
Masonville119701966
Bennett Mill119981996

Yellow Warbler Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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