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

Red-eyed Vireo Population Trend in Connecticut

All statesForest birds

Red-eyed Vireo in Connecticut has surged: up 96% on the route-weighted index since 1968.

+96%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 Red-eyed Vireo 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 →

Red-eyed Vireo has surged in Connecticut: up 96% on the route-weighted index since 1968.

Red-eyed Vireo Population Forecast in Connecticut

If the recent trend holds, Red-eyed Vireo in Connecticut is projected to rise about 11% by 2029 — from 28 in 2024 to a central estimate of 31 (95% range 22–41). A 5-year backtest shows a typical error of ±18.1%, with 100% of held-out values landing inside the 95% band.

+11%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 →
31Projected 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 →
22–4195% 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 →
±18.1%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, Red-eyed Vireo in Connecticut is projected to rise about 11% by 2029 — from 28 in 2024 to a central estimate of 31 (95% range 22–41). A 5-year backtest shows a typical error of ±18.1%, with 100% 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 →
2025302139
2026302140
2027312240
2028312240
2029312241

Red-eyed Vireo Survey Routes in Connecticut

Routes recording Red-eyed Vireo 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 →
Warren12820111972
Woodstock 27720242016
Warren 25120242012
Woodstock4020071968
New Hartford3120241994
Granby2920241988
Willimantic2720181967
New Hartford2619871972
Sherman1920191972
E Hartland1819921966
Uncasville1520241973
Long Hill1520191972
Mid Haddam1520241973
No Woodbury1420241967
Southington1320241973
Danbury1120231968
Mystic920231973
Westbrook920241969
Buckingham620221966
Greenwich620181967

Red-eyed Vireo Population Trend in Other States

alabamaalaskaarkansascoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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