BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Loggerhead Shrike In Great Basin

All regionsGreat BasinGrassland birds

Loggerhead Shrike in Great Basin has declined: down 28% on the route-weighted index since 1970.

-28%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 →
174Routes 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 →
57YearsYears 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 →

No notable trend signals for Loggerhead Shrike in Great Basin. See the full index history below.

Loggerhead Shrike In Great Basin Population Forecast

If the recent trend holds, Loggerhead Shrike in Great Basin is projected to fall about 20% by 2030 — from 1.2 in 2025 to a central estimate of 0.98 (95% range 0.33–1.6). A 5-year backtest shows a typical error of ±23.3%, with 80% of held-out values landing inside the 95% band.

-20%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 →
0.98Projected 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 →
0.33–1.695% 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 →
±23.3%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, Loggerhead Shrike in Great Basin is projected to fall about 20% by 2030 — from 1.2 in 2025 to a central estimate of 0.98 (95% range 0.33–1.6). A 5-year backtest shows a typical error of ±23.3%, with 80% of held-out values landing inside the 95% band.19682030
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 →
20260.980.331.6
20270.980.331.6
20280.980.331.6
20290.980.331.6
20300.980.331.6

Routes In Great Basin

Routes recording Loggerhead Shrike in Great Basin.
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 →
Toiyabe NfNEVADA302024
GandyUTAH242015
SnowvilleUTAH192025
Harney LakeOREGON162024
Majors PlaceNEVADA122025
CalienteNEVADA92025
Malheur NwrOREGON92022
PromontoryUTAH92025
Johnson CanUTAH92022
Arid Land ErWASHINGTON81996
Three ForksOREGON72025
RavendaleCALIFORNIA62025
AlmoIDAHO62025
MizpahNEVADA62024
MinervaNEVADA62024
PotholesWASHINGTON61997
BentonCALIFORNIA52025
Hot SpringIDAHO52014
Kyle CanyonIDAHO52025
SutcliffeNEVADA51972
Ruby Valley 2NEVADA52024
Virgin CreekNEVADA52018
MikkaloOREGON52025
LeamingtonUTAH52017
Moses LakeWASHINGTON51979

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