BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

American Coot In Sierra Nevada

All regionsSierra NevadaWetland birds

American Coot in Sierra Nevada has fallen sharply: down 63% on the route-weighted index since 1974.

-63%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 →
8Routes 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 →
30YearsYears 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 →

American Coot has fallen sharply in Sierra Nevada: down 63% on the route-weighted index since 1974.

American Coot In Sierra Nevada Population Forecast

If the recent trend holds, American Coot in Sierra Nevada is projected to fall about 17% by 2023 — from 0.21 in 2018 to a central estimate of 0.17 (95% range 0.00–0.65). A 5-year backtest shows a typical error of ±207.4%, with 100% of held-out values landing inside the 95% band.

-17%Change by 2023TrendPercent 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 →
0.17Projected 2023 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.6595% 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 →
±207.4%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, American Coot in Sierra Nevada is projected to fall about 17% by 2023 — from 0.21 in 2018 to a central estimate of 0.17 (95% range 0.00–0.65). A 5-year backtest shows a typical error of ±207.4%, with 100% of held-out values landing inside the 95% band.19722023
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 →
20190.190.000.66
20200.180.000.66
20210.180.000.66
20220.180.000.65
20230.170.000.65

Routes In Sierra Nevada

Routes recording American Coot in Sierra Nevada.
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 →
Eagle LakeCALIFORNIA31975
Chaos CraterCALIFORNIA31993
GeneseeCALIFORNIA22018
Hat CreekCALIFORNIA22018
SattleyCALIFORNIA11997
GoumazCALIFORNIA11999
PlacervilleCALIFORNIA12010
Last ChanceCALIFORNIA12018

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