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Species · Connecticut · BBS 2025 Release · 1966–2024

Hermit Thrush Population Trend in Connecticut

All statesForest birds

Hermit Thrush in Connecticut has declined: down 39% on the route-weighted index since 1969.

-39%Since 1969TrendPercent 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 →
17Routes 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 →
55YearsYears 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 ConnecticutNotable 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 Connecticut. See the full index history below.

Hermit Thrush Population Forecast in Connecticut

If the recent trend holds, Hermit Thrush in Connecticut is projected to rise about 86% by 2029 — from 0.33 in 2024 to a central estimate of 0.62 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±99.6%, with 100% of held-out values landing inside the 95% band.

+86%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 →
0.62Projected 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 →
0.00–1.395% 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 →
±99.6%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, Hermit Thrush in Connecticut is projected to rise about 86% by 2029 — from 0.33 in 2024 to a central estimate of 0.62 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±99.6%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.600.001.3
20260.610.001.3
20270.610.001.3
20280.610.001.3
20290.620.001.3

Hermit Thrush Survey Routes in Connecticut

Routes recording Hermit Thrush in Connecticut.
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 →
Sherman420101981
Greenwich419721972
Warren420111972
Woodstock320051968
Mid Haddam319961983
Uncasville219881987
New Hartford220241994
Danbury219721972
Mystic120231999
E Hartland119671967
Buckingham120022002
Willimantic120001967
No Woodbury120111967
Woodstock 2120192018
New Hartford119871976
Warren 2120242022
Granby120231991

Hermit Thrush Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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