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Species · North Carolina · BBS 2026 Release · 1966–2025

Blackburnian Warbler Population Trend in North Carolina

All statesForest birds

Blackburnian Warbler in North Carolina has risen sharply: up 65% on the route-weighted index since 1974.

+65%Since 1974TrendPercent 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 →
43YearsYears 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 North CarolinaNotable 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 →

Blackburnian Warbler has risen sharply in North Carolina: up 65% on the route-weighted index since 1974.

Blackburnian Warbler Population Forecast in North Carolina

If the recent trend holds, Blackburnian Warbler in North Carolina is projected to stay roughly flat through 2030, near 0.18 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±30.4%, with 100% of held-out values landing inside the 95% band.

+7%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 →
0.18Projected 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 →
0.00–0.4795% 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 →
±30.4%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 North Carolina is projected to stay roughly flat through 2030, near 0.18 (95% range 0.00–0.47). A 5-year backtest shows a typical error of ±30.4%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.170.000.47
20270.170.000.47
20280.170.000.47
20290.170.000.47
20300.180.000.47

Blackburnian Warbler Survey Routes in North Carolina

Routes recording Blackburnian Warbler in North Carolina.
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 →
Busick2519961994
Oteen720232001
N. Mills Riv319951994
Highlands320251994
Cherokee320252011
Cullowhee320231974
Linville220251979
Waterville120251994
Kyle120211994
Andrews119981994
Pinelog120042004
Brevard120212021
French Broad River120252001
Fontana120131969
Flay119971997
Marshall120222015

Blackburnian Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorkohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsin

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