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

American Robin In Sierra Nevada

All regionsSierra NevadaForest birds

American Robin in Sierra Nevada has fallen sharply: down 62% on the route-weighted index since 1970.

-62%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 →
40Routes 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 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 Robin has fallen sharply in Sierra Nevada: down 62% on the route-weighted index since 1970.

American Robin In Sierra Nevada Population Forecast

If the recent trend holds, American Robin in Sierra Nevada is projected to fall about 20% by 2029 — from 19 in 2024 to a central estimate of 15 (95% range 3.0–27). A 5-year backtest shows a typical error of ±26.1%, with 100% of held-out values landing inside the 95% band.

-20%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 →
15Projected 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 →
3.0–2795% 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 →
±26.1%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, American Robin in Sierra Nevada is projected to fall about 20% by 2029 — from 19 in 2024 to a central estimate of 15 (95% range 3.0–27). A 5-year backtest shows a typical error of ±26.1%, 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 →
2025174.729
2026164.229
2027163.828
2028163.428
2029153.027

Routes In Sierra Nevada

Routes recording American Robin 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 →
Cottage SpgsCALIFORNIA611975
GeneseeCALIFORNIA522024
GoumazCALIFORNIA522011
Forest Hill 2CALIFORNIA522005
Eagle LakeCALIFORNIA512024
PaxtonCALIFORNIA452024
ChesterCALIFORNIA412017
Little TruckeeCALIFORNIA362023
Lassen ParkCALIFORNIA341989
Forest HillCALIFORNIA322022
Last ChanceCALIFORNIA322019
WoodfordsCALIFORNIA242024
Pine MountainCALIFORNIA242017
ChilcootCALIFORNIA222024
Higgins CornCALIFORNIA212024
WestvilleCALIFORNIA202024
Tuolumne GroveCALIFORNIA202024
RivertonCALIFORNIA172023
Tahoe NfCALIFORNIA171994
PlacervilleCALIFORNIA172024
CoultervilleCALIFORNIA162019
LakeshoreCALIFORNIA152024
SattleyCALIFORNIA142024
Pollock PinesCALIFORNIA142024
DardanelleCALIFORNIA132019

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