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

Common Raven Population Trend in Connecticut

All statesGeneralists

Common Raven in Connecticut has surged: up 704% on the route-weighted index since 2002.

+704%Since 2002TrendPercent 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 →
16Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Raven 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 →

Common Raven has surged in Connecticut: up 704% on the route-weighted index since 2002.

Common Raven Population Forecast in Connecticut

If the recent trend holds, Common Raven in Connecticut is projected to stay roughly flat through 2029, near 1.3 (95% range 0.73–1.9). A 5-year backtest shows a typical error of ±50.2%, with 20% of held-out values landing inside the 95% band.

+0%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 →
1.3Projected 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 →
0.73–1.995% 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 →
±50.2%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, Common Raven in Connecticut is projected to stay roughly flat through 2029, near 1.3 (95% range 0.73–1.9). A 5-year backtest shows a typical error of ±50.2%, with 20% of held-out values landing inside the 95% band.19962029
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 →
20251.20.551.8
20261.20.591.8
20271.20.641.9
20281.30.691.9
20291.30.731.9

Common Raven Survey Routes in Connecticut

Routes recording Common Raven 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 →
Uncasville920242016
Sherman420191996
Woodstock 2320232016
Buckingham220222011
Westbrook220192012
No Woodbury220242004
Long Hill220182016
New Hartford120232002
Willimantic120031996
Greenwich120182018
Danbury120212021
Warren120002000
Mid Haddam120222014
Southington120192016
Warren 2120242012
Granby120232014

Common Raven Population Trend in Other States

alaskaarizonacaliforniacoloradogeorgiaidahokentuckymainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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