BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

Loggerhead Shrike In Northern Rockies

All regionsNorthern RockiesGrassland birds

Loggerhead Shrike in Northern Rockies has risen sharply: up 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 →
74Routes 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 →

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 →

Loggerhead Shrike has risen sharply in Northern Rockies: up 62% on the route-weighted index since 1970.

Loggerhead Shrike In Northern Rockies Population Forecast

If the recent trend holds, Loggerhead Shrike in Northern Rockies is projected to fall about 36% by 2030 — from 0.47 in 2025 to a central estimate of 0.30 (95% range 0.00–0.62). A 5-year backtest shows a typical error of ±24.8%, with 100% of held-out values landing inside the 95% band.

-36%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 →
0.30Projected 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 →
0.00–0.6295% 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 →
±24.8%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, Loggerhead Shrike in Northern Rockies is projected to fall about 36% by 2030 — from 0.47 in 2025 to a central estimate of 0.30 (95% range 0.00–0.62). A 5-year backtest shows a typical error of ±24.8%, with 100% 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 →
20260.300.000.62
20270.300.000.62
20280.300.000.62
20290.300.000.62
20300.300.000.62

Routes In Northern Rockies

Routes recording Loggerhead Shrike in Northern Rockies.
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 →
ArmintoWYOMING102025
RelianceWYOMING82025
BaggsWYOMING72025
Flamin GorgeWYOMING62024
Gas HillsWYOMING52012
MadrasOREGON42025
TensleepWYOMING42025
RawlinsWYOMING42014
Carter 2WYOMING42024
MaybellCOLORADO32025
Clover CreekOREGON32025
ErvayWYOMING32025
LysiteWYOMING32017
WorlandWYOMING32024
PathfinderWYOMING32025
WamsutterWYOMING32025
Patrick Draw 2WYOMING31982
Browns ParkCOLORADO22024
LimaMONTANA22024
GreenoughMONTANA21996
RandolphUTAH22016
Neponset ResUTAH22018
Saleratus CrUTAH22018
MidvaleWYOMING22022
CumberlandWYOMING22025

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