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

Warbling Vireo Population Trend in New Jersey

All statesForest birds

Warbling Vireo in New Jersey has surged: up 13× on the route-weighted index since 1968.

13×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 →
25Routes 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 Warbling Vireo 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 →

Warbling Vireo has surged in New Jersey: up 13× on the route-weighted index since 1968.

Warbling Vireo Population Forecast in New Jersey

If the recent trend holds, Warbling Vireo in New Jersey is projected to rise about 31% by 2029 — from 1.5 in 2024 to a central estimate of 1.9 (95% range 1.1–2.7). A 5-year backtest shows a typical error of ±32.4%, with 100% of held-out values landing inside the 95% band.

+31%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 →
1.9Projected 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 →
1.1–2.795% 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 →
±32.4%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, Warbling Vireo in New Jersey is projected to rise about 31% by 2029 — from 1.5 in 2024 to a central estimate of 1.9 (95% range 1.1–2.7). A 5-year backtest shows a typical error of ±32.4%, 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 →
20251.81.02.6
20261.91.12.7
20271.91.12.7
20281.91.12.7
20291.91.12.7

Warbling Vireo Survey Routes in New Jersey

Routes recording Warbling Vireo 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 →
Bloomsbury1320241969
Ramseysburg920241995
Hope619941970
Pedricktown 2320232013
New Bedford220241994
Midvale220221967
Kemah Lake220241980
High Point220241987
Roosevelt220221986
Toms River120192007
Albion120221972
Sandbrook120221970
Holmansville119951991
Clarksville119721972
Croton120071970
Robbinsville119771966
Dover120231980
Pottersville120231984
Gillette120242001
Keyport120191994
Cranbury120241987
Mt Misery119761976
Pedricktown120122001
Winslow119941990
Croton 2120242009

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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