BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Mallard In Great Basin

All regionsGreat BasinWaterfowl

Mallard in Great Basin has surged: up 109% on the route-weighted index since 1970.

+109%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 →
212Routes 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 surged in Great Basin: up 109% on the route-weighted index since 1970.

Mallard In Great Basin Population Forecast

If the recent trend holds, Mallard in Great Basin is projected to rise about 81% by 2029 — from 4.1 in 2024 to a central estimate of 7.4 (95% range 1.2–14). A 5-year backtest shows a typical error of ±159.5%, with 60% of held-out values landing inside the 95% band.

+81%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 →
7.4Projected 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 →
1.2–1495% 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 →
±159.5%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, Mallard in Great Basin is projected to rise about 81% by 2029 — from 4.1 in 2024 to a central estimate of 7.4 (95% range 1.2–14). A 5-year backtest shows a typical error of ±159.5%, with 60% 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 →
20257.31.114
20267.31.114
20277.41.114
20287.41.114
20297.41.214

Routes In Great Basin

Routes recording Mallard in Great Basin.
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 →
DorrisCALIFORNIA1592019
LikelyCALIFORNIA1572024
Catlow RimOREGON552024
Twin ButtesIDAHO541999
UmatillaOREGON532023
Fish LakeOREGON512024
Bear RiverUTAH512023
GoshenUTAH502024
Cedar HillIDAHO402024
LeadoreIDAHO352024
BlyOREGON332001
YakimaWASHINGTON312024
MadelineCALIFORNIA252024
JosephOREGON252023
Pasadena ValIDAHO242016
ReardanWASHINGTON232022
MacdoelCALIFORNIA222019
Iron GateCALIFORNIA222019
Dobbin CreekNEVADA202016
Crowley LakeCALIFORNIA182022
Warner VallyOREGON182024
Malheur NwrOREGON171998
PromontoryUTAH172023
Moses CouleeWASHINGTON162023
Barnes ValOREGON151987

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