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

Mallard In Northern Rockies

All regionsNorthern RockiesWaterfowl

Mallard in Northern Rockies has risen sharply: up 51% on the route-weighted index since 1970.

+51%Since 1970TrendPercent 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 →
196Routes 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 →
56YearsYears 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 →

Mallard has risen sharply in Northern Rockies: up 51% on the route-weighted index since 1970.

Mallard In Northern Rockies Population Forecast

If the recent trend holds, Mallard in Northern Rockies is projected to rise about 53% by 2029 — from 1.8 in 2024 to a central estimate of 2.8 (95% range 0.56–5.0). A 5-year backtest shows a typical error of ±46.6%, with 100% of held-out values landing inside the 95% band.

+53%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 →
2.8Projected 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 →
0.56–5.095% 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 →
±46.6%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, Mallard in Northern Rockies is projected to rise about 53% by 2029 — from 1.8 in 2024 to a central estimate of 2.8 (95% range 0.56–5.0). A 5-year backtest shows a typical error of ±46.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20252.80.585.0
20262.80.575.0
20272.80.575.0
20282.80.565.0
20292.80.565.0

Routes In Northern Rockies

Routes recording Mallard 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 RiverWYOMING612022
NaplesIDAHO502024
YellowstoneWYOMING412022
Heart ButteMONTANA252019
Hayden ValWYOMING251986
Seedskadee 2WYOMING242024
AnchorWYOMING212016
ClarkWYOMING192010
CascadeIDAHO181984
Pablo Res.MONTANA172024
Hebgen LakeMONTANA162024
SpartaOREGON162001
RandolphUTAH162024
PathfinderWYOMING152022
Neponset ResUTAH142018
LovellWYOMING142018
Saleratus CrUTAH132017
E. Bear LakeUTAH122022
DanielWYOMING121988
BaggsWYOMING122004
FarsonWYOMING112018
MadrasOREGON102022
ShirleyWYOMING102008
CabartonIDAHO92022
Crawford MtsUTAH92015

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