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

Generalists In New Jersey

All statesNew Jersey

51 species in this guild. As a group they are -53%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Generalists as a group have fallen sharply in New Jersey, down 53% since 1968.

Generalists In New Jersey Population Forecast

If the recent trend holds, Generalists in New Jersey is projected to fall about 31% by 2029 — from 8.4 in 2024 to a central estimate of 5.8 (95% range 3.3–8.3). A 5-year backtest shows a typical error of ±15.6%, 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 →
5.8Projected 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 →
3.3–8.395% 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 →
±15.6%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, Generalists in New Jersey is projected to fall about 31% by 2029 — from 8.4 in 2024 to a central estimate of 5.8 (95% range 3.3–8.3). A 5-year backtest shows a typical error of ±15.6%, 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 →
20256.64.09.1
20266.43.98.9
20276.23.78.7
20286.03.58.5
20295.83.38.3

Member Species In New Jersey

Generalists species in New Jersey.
TrendPercent 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 →
Brown ThrasherMimidae-90%
American KestrelFalconidae-88%
Yellow-breasted ChatIcteriidae-88%
Common GrackleIcteridae-82%
Swamp SparrowPasserellidae-80%
Eastern TowheePasserellidae-74%
Northern MockingbirdMimidae-70%
Field SparrowPasserellidae-69%
Broad-winged HawkAccipitridae-69%
Black-billed CuckooCuculidae-68%
House SparrowPasseridae-66%
European StarlingSturnidae-59%
Rock PigeonColumbidae-57%
Belted KingfisherAlcedinidae-52%
Blue JayCorvidae-47%
Ruffed GrousePhasianidae-15%
Baltimore OrioleIcteridae-15%
Red-winged BlackbirdIcteridae-14%
Northern HarrierAccipitridae-13%
Eastern Screech-OwlStrigidae-12%
Yellow-billed CuckooCuculidae-3%
Orchard OrioleIcteridae+4%
American CrowCorvidae+5%
Mourning DoveColumbidae+8%
Song SparrowPasserellidae+16%
Indigo BuntingCardinalidae+17%
Boat-tailed GrackleIcteridae+25%
Chipping SparrowPasserellidae+41%
Sharp-shinned HawkAccipitridae+62%
Rose-breasted GrosbeakCardinalidae+63%
Scarlet TanagerCardinalidae+114%
Turkey VultureCathartidae+119%
Blue GrosbeakCardinalidae+142%
Gray CatbirdMimidae+151%
Great Horned OwlStrigidae+152%
Northern CardinalCardinalidae+156%
Bald EagleAccipitridae+167%
Brown-headed CowbirdIcteridae+168%
Summer TanagerCardinalidae+202%
American GoldfinchFringillidae+249%
Fish CrowCorvidae+327%
Ruby-throated HummingbirdTrochilidae+330%
Cooper's HawkAccipitridae+359%
OspreyPandionidae+488%
Red-shouldered HawkAccipitridae+512%
Black VultureCathartidae+974%
Common RavenCorvidae11×
Red-tailed HawkAccipitridae13×
Wild TurkeyPhasianidae13×
Cedar WaxwingBombycillidae30×
House FinchFringillidae68×

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