BirdAnalyst
Species · North Carolina · BBS 2025 Release · 1966–2024

Winter Wren Population Trend in North Carolina

All statesForest birds

Winter Wren in North Carolina has fallen sharply: down 50% on the route-weighted index since 1979.

-50%Since 1979TrendPercent 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 →
9Routes 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 →
38YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Winter Wren 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 declinecomputed 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 →

Winter Wren has fallen sharply in North Carolina: down 50% on the route-weighted index since 1979.

Winter Wren Population Forecast in North Carolina

If the recent trend holds, Winter Wren in North Carolina is projected to fall about 25% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±50.4%, with 100% of held-out values landing inside the 95% band.

-25%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 →
0.04Projected 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 →
0.00–0.1795% 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 →
±50.4%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, Winter Wren in North Carolina is projected to fall about 25% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±50.4%, with 100% of held-out values landing inside the 95% band.19762029
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 →
20250.050.000.18
20260.050.000.18
20270.050.000.18
20280.040.000.17
20290.040.000.17

Winter Wren Survey Routes in North Carolina

Routes recording Winter Wren 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 →
N. Mills Riv719951994
Andrews219941994
Linville220241976
Waterville120151998
Highlands120171998
Kyle120241994
French Broad River120242003
Cherokee120222021
Cullowhee120042004

Winter Wren Population Trend in Other States

connecticutmainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorkohiopennsylvaniatennesseevermontvirginiawest-virginiawisconsin

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