BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Marsh Wren In Prairie Potholes

All regionsPrairie PotholesForest birds

Marsh Wren in Prairie Potholes has surged: up 621% on the route-weighted index since 1969.

+621%Since 1969TrendPercent 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 →
89Routes 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 →
58YearsYears 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 →

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 →

Marsh Wren has surged in Prairie Potholes: up 621% on the route-weighted index since 1969.

Marsh Wren In Prairie Potholes Population Forecast

If the recent trend holds, Marsh Wren in Prairie Potholes is projected to stay roughly flat through 2030, near 11 (95% range 8.2–13). A 5-year backtest shows a typical error of ±4.4%, 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 →
11Projected 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 →
8.2–1395% 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 →
±4.4%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, Marsh Wren in Prairie Potholes is projected to stay roughly flat through 2030, near 11 (95% range 8.2–13). A 5-year backtest shows a typical error of ±4.4%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20269.97.512
2027107.613
2028107.813
2029108.013
2030118.213

Routes In Prairie Potholes

Routes recording Marsh Wren in Prairie Potholes.
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 →
Horsehead LkNORTH-DAKOTA1912025
LakotaNORTH-DAKOTA482009
WimbledonNORTH-DAKOTA462025
ForbesSOUTH-DAKOTA452025
TracyMINNESOTA442025
Sheyenne LkNORTH-DAKOTA432025
FormanNORTH-DAKOTA362025
BuchananNORTH-DAKOTA352025
MontpelierNORTH-DAKOTA342025
CooperstownNORTH-DAKOTA312025
ReganNORTH-DAKOTA302025
EdgeleyNORTH-DAKOTA282025
DanzigNORTH-DAKOTA272013
VeblenSOUTH-DAKOTA262023
Powers LakeNORTH-DAKOTA222025
Danzig 2NORTH-DAKOTA222025
Big StoneMINNESOTA202012
BrittonSOUTH-DAKOTA202023
Lakota 2NORTH-DAKOTA182024
BraddockNORTH-DAKOTA172023
VolgaSOUTH-DAKOTA172025
RaymondSOUTH-DAKOTA152021
ChokioMINNESOTA142025
NilesNORTH-DAKOTA142023
FairmontMINNESOTA122025

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