BirdAnalyst
Species · Pennsylvania · BBS 2026 Release · 1966–2025

Winter Wren Population Trend in Pennsylvania

All statesForest birds

Winter Wren in Pennsylvania has surged: up 13× on the route-weighted index since 1976.

13×Since 1976TrendPercent 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 →
58Routes 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 →
50YearsYears 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 PennsylvaniaNotable 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 Winter Wren in Pennsylvania. See the full index history below.

Winter Wren Population Forecast in Pennsylvania

If the recent trend holds, Winter Wren in Pennsylvania is projected to rise about 11% by 2030 — from 0.34 in 2025 to a central estimate of 0.38 (95% range 0.14–0.63). A 5-year backtest shows a typical error of ±19.9%, with 100% of held-out values landing inside the 95% band.

+11%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 →
0.38Projected 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 →
0.14–0.6395% 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 →
±19.9%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 Pennsylvania is projected to rise about 11% by 2030 — from 0.34 in 2025 to a central estimate of 0.38 (95% range 0.14–0.63). A 5-year backtest shows a typical error of ±19.9%, with 100% of held-out values landing inside the 95% band.19702030
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 →
20260.360.120.60
20270.370.130.61
20280.370.130.61
20290.380.140.62
20300.380.140.63

Winter Wren Survey Routes in Pennsylvania

Routes recording Winter Wren in Pennsylvania.
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 →
Russell City820251974
Lynch420251970
Roulette420211980
Susquehanna420231976
Berwick320001994
Rasselas320211989
Mawr Glen320251983
Honesdale320231990
Ansonia320252003
Teepleville219931993
N Pine Grove220251995
Logue220251976
Little Marsh220211995
Rush220231980
Marsh Hill220251986
Canadensis220241997
Ltl Pine Cr220231990
Duboistown220241987
Ellenton120251983
Wyalusing119971989
Whig Hill120131990
Rothrock Sf120141992
Tussey Mtn.120132004
Pottersdale120042004
Odin120251991

Winter Wren Population Trend in Other States

connecticutmainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiotennesseevermontvirginiawest-virginiawisconsin

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