BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Mallard In BCR 4

All regionsBCR 4Waterfowl

Mallard in BCR 4 has collapsed: down 78% on the route-weighted index since 1978.

-78%Since 1978TrendPercent 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 →
51Routes 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 →
45YearsYears 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 declinecomputed 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 collapsed in BCR 4: down 77% on the route-weighted index since 1978.

Mallard In BCR 4 Population Forecast

If the recent trend holds, Mallard in BCR 4 is projected to fall about 69% by 2029 — from 0.89 in 2024 to a central estimate of 0.27 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.

-69%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 →
0.27Projected 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 →
0.00–1.995% 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 →
±55.1%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, Mallard in BCR 4 is projected to fall about 69% by 2029 — from 0.89 in 2024 to a central estimate of 0.27 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.19752029
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 →
20250.380.002.0
20260.350.002.0
20270.330.002.0
20280.300.001.9
20290.270.001.9

Routes In BCR 4

Routes recording Mallard in BCR 4.
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 →
Bear CreekALASKA301991
CottonwoodALASKA231988
HomerALASKA151982
Porcupine R.ALASKA102001
DeltaALASKA82024
NebesnaALASKA71975
Nicholai SlALASKA72019
KachemakALASKA72024
Kanuti LakeALASKA62024
L SalchaALASKA42015
ToklatALASKA32013
Chena Hot Spring 2ALASKA32022
Unalakleet RiverALASKA32023
Mud RiverALASKA32024
Murphy DomeALASKA32005
CircleALASKA22000
MaclarenALASKA22021
Kenny LakeALASKA22021
SourdoughALASKA22023
ChickenALASKA22023
Burma RoadALASKA22004
ColdfootALASKA22023
Donelly DomeALASKA22024
Hather CreekALASKA22024
McgrathALASKA22019

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