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

Hermit Thrush Population Trend in New Jersey

All statesForest birds

Hermit Thrush in New Jersey has declined: down 33% on the route-weighted index since 1980.

-33%Since 1980TrendPercent 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 →
4Routes 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 →
25YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hermit Thrush 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 Hermit Thrush in New Jersey. See the full index history below.

Hermit Thrush Population Forecast in New Jersey

If the recent trend holds, Hermit Thrush in New Jersey is projected to stay roughly flat through 2029, near 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±275.8%, with 80% of held-out values landing inside the 95% band.

n/aChange 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 →
0.09Projected 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 →
0.00–0.2795% 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 →
±275.8%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, Hermit Thrush in New Jersey is projected to stay roughly flat through 2029, near 0.09 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±275.8%, with 80% of held-out values landing inside the 95% band.19772029
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 →
20250.100.000.28
20260.100.000.28
20270.090.000.27
20280.090.000.27
20290.090.000.27

Hermit Thrush Survey Routes in New Jersey

Routes recording Hermit Thrush 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 3120242024
Kemah Lake119941992
Friendship120181998
High Point120061977

Hermit Thrush Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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