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Species · Connecticut · BBS 2025 Release · 1966–2024

Acadian Flycatcher Population Trend in Connecticut

All statesAerial insectivores

Acadian Flycatcher in Connecticut has surged: up 121% on the route-weighted index since 1983.

+121%Since 1983TrendPercent 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 →
12Routes 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 →
30YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Acadian Flycatcher 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 →

Acadian Flycatcher has surged in Connecticut: up 121% on the route-weighted index since 1983.

Acadian Flycatcher Population Forecast in Connecticut

If the recent trend holds, Acadian Flycatcher in Connecticut is projected to rise about 121% by 2029 — from 0.11 in 2024 to a central estimate of 0.24 (95% range 0.03–0.46). A 5-year backtest shows a typical error of ±41.5%, with 80% of held-out values landing inside the 95% band.

+121%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 →
0.24Projected 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 →
0.03–0.4695% 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 →
±41.5%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, Acadian Flycatcher in Connecticut is projected to rise about 121% by 2029 — from 0.11 in 2024 to a central estimate of 0.24 (95% range 0.03–0.46). A 5-year backtest shows a typical error of ±41.5%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.230.020.45
20260.240.020.46
20270.240.020.46
20280.240.020.46
20290.240.030.46

Acadian Flycatcher Survey Routes in Connecticut

Routes recording Acadian Flycatcher 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 →
Warren420082001
Woodstock219701970
Mid Haddam220232005
Mystic120021983
Buckingham120222022
Uncasville120241987
Westbrook119991985
No Woodbury120012001
Sherman120152004
Woodstock 2120162016
Danbury119771977
Long Hill120102005

Acadian Flycatcher Population Trend in Other States

alabamaarkansasdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamarylandmassachusettsmichiganminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginiawest-virginiawisconsin

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