BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Red-winged Blackbird In Sierra Nevada

All regionsSierra NevadaWetland birds

Red-winged Blackbird in Sierra Nevada has surged: up 430% on the route-weighted index since 1972.

+430%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 →
55YearsYears 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 430% on the route-weighted index since 1972.

Red-winged Blackbird In Sierra Nevada Population Forecast

If the recent trend holds, Red-winged Blackbird in Sierra Nevada is projected to fall about 37% by 2030 — from 16 in 2025 to a central estimate of 10 (95% range 4.7–16). A 5-year backtest shows a typical error of ±37.8%, with 40% of held-out values landing inside the 95% band.

-37%Change by 2030TrendPercent 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 →
10Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
4.7–1695% 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 →
±37.8%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 37% by 2030 — from 16 in 2025 to a central estimate of 10 (95% range 4.7–16). A 5-year backtest shows a typical error of ±37.8%, with 40% of held-out values landing inside the 95% band.19692030
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 →
20269.84.115
20279.94.316
2028104.416
2029104.616
2030104.716

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 →
PaxtonCALIFORNIA2362025
GeneseeCALIFORNIA392024
SattleyCALIFORNIA292025
Little TruckeeCALIFORNIA122025
KernvilleCALIFORNIA82008
Tuolumne GroveCALIFORNIA72025
Hat CreekCALIFORNIA62018
Last ChanceCALIFORNIA62019
CoultervilleCALIFORNIA52019
DardanelleCALIFORNIA42018
Butte MeadowCALIFORNIA42014
LakeshoreCALIFORNIA42024
GoumazCALIFORNIA42011
ChilcootCALIFORNIA42024
Silver CityCALIFORNIA32013
Meadow ValleyCALIFORNIA32025
WawonaCALIFORNIA32023
Pine MountainCALIFORNIA32017
Lassen ParkCALIFORNIA21987
Eagle LakeCALIFORNIA22025
WoodfordsCALIFORNIA22025
Greenhorn MtCALIFORNIA22008
Higgins CornCALIFORNIA22025
Bass LakeCALIFORNIA12011
JohnsvilleCALIFORNIA12024

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.