BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

Northern Shrike In BCR 2

All regionsBCR 2Generalists

Northern Shrike in BCR 2 has declined: down 27% on the route-weighted index since 1991.

-27%Since 1991TrendPercent 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 →
10Routes 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 →
18YearsYears 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 Northern Shrike in BCR 2. See the full index history below.

Forecast

If the recent trend holds, Northern Shrike in BCR 2 is projected to fall about 16% by 2029 — from 0.33 in 2024 to a central estimate of 0.28 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±58.2%, with 40% of held-out values landing inside the 95% band.

-16%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 →
0.28Projected 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 →
0.00–0.7195% 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 →
±58.2%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, Northern Shrike in BCR 2 is projected to fall about 16% by 2029 — from 0.33 in 2024 to a central estimate of 0.28 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±58.2%, with 40% of held-out values landing inside the 95% band.19852029
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 →
20250.270.000.70
20260.270.000.71
20270.280.000.71
20280.280.000.71
20290.280.000.71

Routes In BCR 2

Routes recording Northern Shrike in BCR 2.
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 →
Cold BayALASKA22024
TellerALASKA22017
ChiniakALASKA12022
King SalmonALASKA12024
Kodiak 2ALASKA11991
CouncilALASKA12008
NomeALASKA12023
Salmon LakeALASKA12017
KotzebueALASKA12022
Cold Bay (Short)ALASKA11990

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