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Species · Connecticut · BBS 2026 Release · 1966–2025

Cooper's Hawk Population Trend in Connecticut

All statesBirds of prey

Cooper's Hawk in Connecticut has risen sharply: up 57% on the route-weighted index since 1981.

+57%Since 1981TrendPercent 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 →
17Routes 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 →
25YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cooper's Hawk 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 →

Cooper's Hawk has risen sharply in Connecticut: up 56% on the route-weighted index since 1981.

Cooper's Hawk Population Forecast in Connecticut

If the recent trend holds, Cooper's Hawk in Connecticut is projected to rise about 25% by 2030 — from 0.13 in 2025 to a central estimate of 0.16 (95% range 0.04–0.27). A 5-year backtest shows a typical error of ±84.3%, with 100% of held-out values landing inside the 95% band.

+25%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 →
0.16Projected 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 →
0.04–0.2795% 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 →
±84.3%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, Cooper's Hawk in Connecticut is projected to rise about 25% by 2030 — from 0.13 in 2025 to a central estimate of 0.16 (95% range 0.04–0.27). A 5-year backtest shows a typical error of ±84.3%, with 100% of held-out values landing inside the 95% band.19732030
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 →
20260.150.040.26
20270.150.040.26
20280.150.040.27
20290.150.040.27
20300.160.040.27

Cooper's Hawk Survey Routes in Connecticut

Routes recording Cooper's Hawk 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 →
Mystic120211987
Buckingham120142014
Uncasville120152015
Woodstock119811973
Westbrook120192019
Willimantic120052005
No Woodbury120252002
Sherman119821982
Greenwich120092009
Danbury120152015
Warren120021980
New Hartford120171999
Mid Haddam120151973
Southington120162005
Woodstock 2120162016
Warren 2120222022
Granby120212015

Cooper's Hawk Population Trend in Other States

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

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