BirdAnalyst
Species · Connecticut · BBS 2025 Release · 1966–2024

Least Flycatcher Population Trend in Connecticut

All statesAerial insectivores

Least Flycatcher in Connecticut has collapsed: down 84% on the route-weighted index since 1968.

-84%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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Least 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 declinecomputed 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 →

Least Flycatcher has collapsed in Connecticut: down 84% on the route-weighted index since 1968.

Least Flycatcher Population Forecast in Connecticut

If the recent trend holds, Least Flycatcher in Connecticut is projected to fall about 100% by 2029 — from 1.3 in 2024 to a central estimate of 0.00 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±148.8%, with 80% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.595% 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 →
±148.8%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, Least Flycatcher in Connecticut is projected to fall about 100% by 2029 — from 1.3 in 2024 to a central estimate of 0.00 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±148.8%, with 80% of held-out values landing inside the 95% band.19662029
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 →
20250.000.001.5
20260.000.001.5
20270.000.001.5
20280.000.001.5
20290.000.001.5

Least Flycatcher Survey Routes in Connecticut

Routes recording Least 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 →
Woodstock 21020242016
Sherman320181972
New Hartford319851972
Warren220111972
Long Hill219871973
New Hartford220131995
Warren 2220242013
Granby220191990
Mystic120211973
E Hartland119921966
Buckingham120031966
Uncasville120091977
Woodstock120071968
Westbrook119841981
Willimantic120181967
No Woodbury120181967
Greenwich119781968
Danbury119851968
Mid Haddam120071973
Southington119851976

Least Flycatcher Population Trend in Other States

alaskaarkansascaliforniacoloradogeorgiaidahoillinoisindianaiowakentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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