BirdAnalyst
Species · Idaho · BBS 2026 Release · 1966–2025

Loggerhead Shrike Population Trend in Idaho

All statesGrassland birds

Loggerhead Shrike in Idaho has surged: up 195% on the route-weighted index since 1971.

+195%Since 1971TrendPercent 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 →
23Routes In StateSurvey 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 Loggerhead Shrike Trends in IdahoNotable 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 surged in Idaho: up 195% on the route-weighted index since 1971.

Loggerhead Shrike Population Forecast in Idaho

If the recent trend holds, Loggerhead Shrike in Idaho is projected to fall about 22% by 2030 — from 0.71 in 2025 to a central estimate of 0.56 (95% range 0.04–1.1). A 5-year backtest shows a typical error of ±36.9%, with 100% of held-out values landing inside the 95% band.

-22%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 →
0.56Projected 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 →
0.04–1.195% 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 →
±36.9%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 Idaho is projected to fall about 22% by 2030 — from 0.71 in 2025 to a central estimate of 0.56 (95% range 0.04–1.1). A 5-year backtest shows a typical error of ±36.9%, with 100% 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 →
20260.540.031.1
20270.550.031.1
20280.550.041.1
20290.560.041.1
20300.560.041.1

Loggerhead Shrike Survey Routes in Idaho

Routes recording Loggerhead Shrike in Idaho.
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 →
Almo620252015
Kyle Canyon520251985
Hot Spring520141988
Twin Buttes320251985
Tractor Flat320251985
Circular Bu220251985
Craters220171980
Acequia220071979
Carey220251990
Pasadena Val220072003
Lost River120241987
Dubois120251969
Springfield119801976
Triangle120251992
Henry119811981
Joel119921990
Crane Creek120191992
Silver City120181994
Picabo120251988
Mud Lake120042004
Dougal Res120151990
Cedar Hill120231993
Daniels Res120252000

Loggerhead Shrike Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradofloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanevadanew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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