BirdAnalyst
Species · Montana · BBS 2025 Release · 1966–2024

Ruddy Duck Population Trend in Montana

All statesWaterfowl

Ruddy Duck in Montana has surged: up 192% on the route-weighted index since 1974.

+192%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 →
35Routes 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 →
46YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ruddy Duck Trends in MontanaNotable 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 →

Ruddy Duck has surged in Montana: up 192% on the route-weighted index since 1974.

Ruddy Duck Population Forecast in Montana

If the recent trend holds, Ruddy Duck in Montana is projected to fall about 41% by 2029 — from 0.18 in 2024 to a central estimate of 0.10 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±52.1%, with 80% of held-out values landing inside the 95% band.

-41%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 →
0.10Projected 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 →
0.00–0.3095% 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 →
±52.1%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, Ruddy Duck in Montana is projected to fall about 41% by 2029 — from 0.18 in 2024 to a central estimate of 0.10 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±52.1%, with 80% of held-out values landing inside the 95% band.19702029
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 →
20250.110.000.30
20260.100.000.30
20270.100.000.30
20280.100.000.30
20290.100.000.30

Ruddy Duck Survey Routes in Montana

Routes recording Ruddy Duck in Montana.
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 →
Westby2520232015
Brusett720241989
Roy420192007
Shelby420182018
Sunburst320021978
Virgelle320182018
Highwood320121970
Beaverhead319961996
Red Rock320192017
Coleman Coulee320232019
Glasgow219971997
Polson219961996
Savage219801980
Ingomar220161980
Winifred 2220242024
Powderville219741974
Wise River220062006
Whitlash220242011
Kalispell120021973
Hay Lake120151994
Malta120241979
Oswego119781978
Willow Creek 2120242003
Augusta120181977
Great Falls120191989

Ruddy Duck Population Trend in Other States

arizonacaliforniacoloradoidahoillinoisindianaiowakansasmichiganminnesotanebraskanevadanew-mexiconew-yorknorth-dakotaohiooklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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