BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Mallard In Coastal California

All regionsCoastal CaliforniaWaterfowl

Mallard in Coastal California has surged: up 80% on the route-weighted index since 1970.

+80%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 →
104Routes 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 Coastal California: up 80% on the route-weighted index since 1970.

Mallard In Coastal California Population Forecast

If the recent trend holds, Mallard in Coastal California is projected to rise about 110% by 2029 — from 3.9 in 2024 to a central estimate of 8.1 (95% range 0.00–16). A 5-year backtest shows a typical error of ±202.7%, with 100% of held-out values landing inside the 95% band.

+110%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 →
8.1Projected 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 →
0.00–1695% 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 →
±202.7%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, Mallard in Coastal California is projected to rise about 110% by 2029 — from 3.9 in 2024 to a central estimate of 8.1 (95% range 0.00–16). A 5-year backtest shows a typical error of ±202.7%, 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 →
20257.80.0016
20267.90.0016
20278.00.0016
20288.00.0016
20298.10.0016

Routes In Coastal California

Routes recording Mallard in Coastal California.
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 →
CoalingaCALIFORNIA1252012
CopperopolisCALIFORNIA932024
GlennCALIFORNIA292023
Harbor LakeCALIFORNIA271991
AthloneCALIFORNIA252007
MoragaCALIFORNIA192023
Lockwood ValCALIFORNIA172012
BakersfieldCALIFORNIA132018
Elsinore MtnCALIFORNIA132022
GravesboroCALIFORNIA121995
PowayCALIFORNIA121980
AtwaterCALIFORNIA122012
Ora LomaCALIFORNIA122024
Buena VistaCALIFORNIA112019
Collegeville 2CALIFORNIA102023
ShafterCALIFORNIA91989
CoyoteCALIFORNIA92024
Staten Is.CALIFORNIA92024
South LakeCALIFORNIA92006
AnzaCALIFORNIA72004
MorenoCALIFORNIA62024
El ToroCALIFORNIA61999
Cp. PendletonCALIFORNIA61988
AdelaidaCALIFORNIA62024
SangerCALIFORNIA62023

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