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Species · Connecticut · BBS 2025 Release · 1966–2024

Louisiana Waterthrush Population Trend in Connecticut

All statesForest birds

Louisiana Waterthrush in Connecticut has surged: up 235% on the route-weighted index since 1969.

+235%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 →
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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Louisiana Waterthrush 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 →

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 →

Louisiana Waterthrush has surged in Connecticut: up 235% on the route-weighted index since 1969.

Louisiana Waterthrush Population Forecast in Connecticut

If the recent trend holds, Louisiana Waterthrush in Connecticut is projected to fall about 30% by 2029 — from 1.2 in 2024 to a central estimate of 0.85 (95% range 0.39–1.3). A 5-year backtest shows a typical error of ±25.5%, with 100% of held-out values landing inside the 95% band.

-30%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 →
0.85Projected 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 →
0.39–1.395% 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 →
±25.5%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, Louisiana Waterthrush in Connecticut is projected to fall about 30% by 2029 — from 1.2 in 2024 to a central estimate of 0.85 (95% range 0.39–1.3). A 5-year backtest shows a typical error of ±25.5%, 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 →
20250.820.371.3
20260.830.371.3
20270.840.381.3
20280.840.391.3
20290.850.391.3

Louisiana Waterthrush Survey Routes in Connecticut

Routes recording Louisiana Waterthrush 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 →
Warren720111973
Mid Haddam520241976
Willimantic420181971
Granby320231988
Woodstock220071970
Sherman220191972
Long Hill220191980
Southington220241974
New Hartford219861972
Woodstock 2220242016
Mystic120221987
E Hartland119921967
Buckingham120122012
Uncasville120241973
Westbrook120231984
No Woodbury120221974
Greenwich119951967
Danbury120231968
New Hartford120231994
Warren 2120242024

Louisiana Waterthrush Population Trend in Other States

alabamaarkansasdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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