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

Fish Crow Population Trend in Connecticut

All statesGeneralists

Fish Crow in Connecticut has surged: up 15× on the route-weighted index since 1982.

15×Since 1982TrendPercent 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 →
14Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Fish Crow 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 →

Fish Crow has surged in Connecticut: up 15× on the route-weighted index since 1982.

Fish Crow Population Forecast in Connecticut

If the recent trend holds, Fish Crow in Connecticut is projected to rise about 20% by 2029 — from 1.4 in 2024 to a central estimate of 1.7 (95% range 0.50–3.0). A 5-year backtest shows a typical error of ±18.9%, with 100% of held-out values landing inside the 95% band.

+20%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 →
1.7Projected 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 →
0.50–3.095% 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 →
±18.9%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, Fish Crow in Connecticut is projected to rise about 20% by 2029 — from 1.4 in 2024 to a central estimate of 1.7 (95% range 0.50–3.0). A 5-year backtest shows a typical error of ±18.9%, with 100% of held-out values landing inside the 95% band.19772029
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 →
20251.60.352.8
20261.60.392.8
20271.70.432.9
20281.70.462.9
20291.70.503.0

Fish Crow Survey Routes in Connecticut

Routes recording Fish Crow 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 →
Westbrook1020241977
Danbury820232005
Long Hill820182015
Southington420222008
Greenwich320181982
Mid Haddam320242007
Willimantic220142011
Mystic120231987
Uncasville120222012
No Woodbury120231999
New Hartford120182018
Warren119991999
Warren 2120162016
Granby120102010

Fish Crow Population Trend in Other States

alabamaarkansasdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginia

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