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Species · Connecticut · BBS 2025 Release · 1966–2024

Blackburnian Warbler Population Trend in Connecticut

All statesForest birds

Blackburnian Warbler in Connecticut has held roughly steady: down 9% on the route-weighted index since 1970.

-9%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 →
52YearsYears 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 rise about 160% by 2029 — from 0.11 in 2024 to a central estimate of 0.29 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±89.8%, with 100% of held-out values landing inside the 95% band.

+160%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 →
0.29Projected 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 →
0.00–0.6495% 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 →
±89.8%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 rise about 160% by 2029 — from 0.11 in 2024 to a central estimate of 0.29 (95% range 0.00–0.64). A 5-year backtest shows a typical error of ±89.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.280.000.63
20260.290.000.63
20270.290.000.64
20280.290.000.64
20290.290.000.64

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
E Hartland119851985
New Hartford120231995
Willimantic120071971
No Woodbury119771977
Woodstock 2120182018
Danbury119721972
Warren 2120242022

Blackburnian Warbler Population Trend in Other States

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

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