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Species · Connecticut · BBS 2026 Release · 1966–2025

Common Yellowthroat Population Trend in Connecticut

All statesForest birds

Common Yellowthroat in Connecticut has edged down: down 21% on the route-weighted index since 1968.

-21%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 →
20Routes 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 →
59YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Yellowthroat 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 Common Yellowthroat in Connecticut. See the full index history below.

Common Yellowthroat Population Forecast in Connecticut

If the recent trend holds, Common Yellowthroat in Connecticut is projected to rise about 21% by 2030 — from 11 in 2025 to a central estimate of 13 (95% range 7.4–18). A 5-year backtest shows a typical error of ±28.5%, with 100% of held-out values landing inside the 95% band.

+21%Change by 2030TrendPercent 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 →
13Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
7.4–1895% 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 →
±28.5%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, Common Yellowthroat in Connecticut is projected to rise about 21% by 2030 — from 11 in 2025 to a central estimate of 13 (95% range 7.4–18). A 5-year backtest shows a typical error of ±28.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
2026137.619
2027137.519
2028137.519
2029137.418
2030137.418

Common Yellowthroat Survey Routes in Connecticut

Routes recording Common Yellowthroat 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 →
Warren6820111972
Woodstock 22720252016
New Hartford2619871972
Sherman1820191972
Buckingham1720221966
Warren 21620252012
Willimantic1520181967
E Hartland1319921966
Woodstock1320071968
Uncasville1220251973
Granby1120251988
No Woodbury920251967
Mid Haddam820251973
Long Hill520191972
Mystic420231973
Danbury420231968
Southington220251973
New Hartford220241994
Westbrook120241970
Greenwich120181967

Common Yellowthroat Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.