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Species · Connecticut · BBS 2026 Release · 1966–2025

Blackburnian Warbler Population Trend in Connecticut

All statesForest birds

Blackburnian Warbler in Connecticut has edged down: down 16% on the route-weighted index since 1970.

-16%Since 1970TrendPercent 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 →
12Routes 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 →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blackburnian Warbler 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 →

No notable trend signals for Blackburnian Warbler in Connecticut. See the full index history below.

Blackburnian Warbler Population Forecast in Connecticut

If the recent trend holds, Blackburnian Warbler in Connecticut is projected to fall about 21% by 2030 — from 0.38 in 2025 to a central estimate of 0.30 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±93.4%, with 100% of held-out values landing inside the 95% band.

-21%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 →
0.30Projected 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 →
0.00–0.6495% 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 →
±93.4%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, Blackburnian Warbler in Connecticut is projected to fall about 21% by 2030 — from 0.38 in 2025 to a central estimate of 0.30 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±93.4%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.290.000.64
20270.290.000.64
20280.290.000.64
20290.300.000.64
20300.300.000.64

Blackburnian Warbler Survey Routes in Connecticut

Routes recording Blackburnian Warbler 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 →
Warren420111972
Granby320231989
Woodstock219951968
Long Hill220192005
New Hartford219871985
Warren 2220252022
E Hartland119851985
New Hartford120231995
Willimantic120071971
No Woodbury119771977
Woodstock 2120252018
Danbury119721972

Blackburnian Warbler Population Trend in Other States

georgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsin

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