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

Red-winged Blackbird In Sierra Nevada

All regionsSierra NevadaGeneralists

Red-winged Blackbird in Sierra Nevada has surged: up 322% on the route-weighted index since 1972.

+322%Since 1972TrendPercent 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 →
29Routes 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 →
54YearsYears 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 →

Red-winged Blackbird has surged in Sierra Nevada: up 322% on the route-weighted index since 1972.

Forecast

If the recent trend holds, Red-winged Blackbird in Sierra Nevada is projected to fall about 30% by 2029 — from 14 in 2024 to a central estimate of 9.6 (95% range 4.2–15). A 5-year backtest shows a typical error of ±30.7%, with 60% of held-out values landing inside the 95% band.

-30%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 →
9.6Projected 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 →
4.2–1595% 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 →
±30.7%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, Red-winged Blackbird in Sierra Nevada is projected to fall about 30% by 2029 — from 14 in 2024 to a central estimate of 9.6 (95% range 4.2–15). A 5-year backtest shows a typical error of ±30.7%, with 60% of held-out values landing inside the 95% band.19692029
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 →
20259.13.714
20269.23.915
20279.44.015
20289.54.115
20299.64.215

Routes In Sierra Nevada

Routes recording Red-winged Blackbird 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 →
PaxtonCALIFORNIA1742024
GeneseeCALIFORNIA392024
SattleyCALIFORNIA192024
Little TruckeeCALIFORNIA132023
Higgins CornCALIFORNIA82024
KernvilleCALIFORNIA82008
Tuolumne GroveCALIFORNIA72024
Hat CreekCALIFORNIA62018
Last ChanceCALIFORNIA62019
CoultervilleCALIFORNIA52019
DardanelleCALIFORNIA42018
Butte MeadowCALIFORNIA42014
LakeshoreCALIFORNIA42024
GoumazCALIFORNIA42011
ChilcootCALIFORNIA42024
Silver CityCALIFORNIA32013
WawonaCALIFORNIA32023
Pine MountainCALIFORNIA32017
Lassen ParkCALIFORNIA21987
Eagle LakeCALIFORNIA22018
WoodfordsCALIFORNIA22024
Greenhorn MtCALIFORNIA22008
Bass LakeCALIFORNIA12011
JohnsvilleCALIFORNIA12024
Kings CanyonCALIFORNIA12002

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