BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Marsh Wren In Appalachian Mountains

All regionsAppalachian MountainsForest birds

Marsh Wren in Appalachian Mountains has fallen sharply: down 69% on the route-weighted index since 1971.

-69%Since 1971TrendPercent 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 →
14Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Marsh Wren in Appalachian Mountains. See the full index history below.

Forecast

If the recent trend holds, Marsh Wren in Appalachian Mountains is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±59.5%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.0195% 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 →
±59.5%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, Marsh Wren in Appalachian Mountains is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.01). A 5-year backtest shows a typical error of ±59.5%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.000.000.01
20260.000.000.01
20270.000.000.01
20280.000.000.01
20290.000.000.01

Routes In Appalachian Mountains

Routes recording Marsh Wren in Appalachian Mountains.
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 →
Bolins MillsOHIO31997
HopeNEW-JERSEY11976
MidvaleNEW-JERSEY11980
WarwickNEW-YORK11974
RiftonNEW-YORK11986
S BerneNEW-YORK11997
Phillips CrNEW-YORK11968
CattaraugusNEW-YORK11972
Warwick 2NEW-YORK12013
Orange LakeNEW-YORK11987
LoguePENNSYLVANIA11971
Little MarshPENNSYLVANIA12024
Hop BottomPENNSYLVANIA11967
HonesdalePENNSYLVANIA12004

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