BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Gadwall In Northern Rockies

All regionsNorthern RockiesWaterfowl

Gadwall in Northern Rockies has surged: up 463% on the route-weighted index since 1974.

+463%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 →
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 →
51YearsYears 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 →

Gadwall has surged in Northern Rockies: up 463% on the route-weighted index since 1974.

Gadwall In Northern Rockies Population Forecast

If the recent trend holds, Gadwall in Northern Rockies is projected to rise about 317% by 2029 — from 0.24 in 2024 to a central estimate of 1.0 (95% range 0.19–1.8). A 5-year backtest shows a typical error of ±150.7%, with 80% of held-out values landing inside the 95% band.

+317%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 →
1.0Projected 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 →
0.19–1.895% 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 →
±150.7%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, Gadwall in Northern Rockies is projected to rise about 317% by 2029 — from 0.24 in 2024 to a central estimate of 1.0 (95% range 0.19–1.8). A 5-year backtest shows a typical error of ±150.7%, 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 →
20250.950.141.8
20260.960.151.8
20270.980.161.8
20280.990.181.8
20291.00.191.8

Routes In Northern Rockies

Routes recording Gadwall in Northern Rockies.
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 →
Rock RiverWYOMING992022
Neponset ResUTAH402017
FeathervilleIDAHO82001
E. Bear LakeUTAH82022
HarmonyWYOMING82022
SeedskadeeWYOMING82016
YellowstoneWYOMING82022
Rawlins 2WYOMING72017
CabartonIDAHO62023
Pablo Res.MONTANA62023
Green RiverWYOMING61984
NaplesIDAHO52024
Red RockMONTANA52022
Saleratus CrUTAH52016
LayCOLORADO42024
BeaverheadMONTANA42023
RandolphUTAH42024
CrowheartWYOMING42004
WalcottWYOMING42021
Carter 2WYOMING42024
Hayden ValWYOMING41986
AugustaMONTANA32022
Willow Creek 2MONTANA32021
Wolf CreekMONTANA32019
BridgeportOREGON32012

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