BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Loggerhead Shrike In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Loggerhead Shrike in Sierra Madre Occidental has fallen sharply: down 60% on the route-weighted index since 1970.

-60%Since 1970
23Routes In Region
56Years

Notable Signals

long arc declinecomputed index

Loggerhead Shrike has fallen sharply in Sierra Madre Occidental: down 60% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Loggerhead Shrike in Sierra Madre Occidental is projected to fall about 76% by 2029 — from 1.4 in 2024 to a central estimate of 0.33 (95% range 0.00–1.9). A 5-year backtest shows a typical error of ±61.2%, with 100% of held-out values landing inside the 95% band.

-76%Change by 2029
0.33Projected 2029 index
0.00–1.995% range
±61.2%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20250.430.002.0
20260.410.002.0
20270.380.002.0
20280.360.002.0
20290.330.001.9

Routes In Sierra Madre Occidental

Routes recording Loggerhead Shrike in Sierra Madre Occidental.
Mormon LakeARIZONA91974
San SimonARIZONA72024
SunizonaARIZONA51997
Sunizona 2ARIZONA42024
Peña BlancaARIZONA32024
Bartlett ResARIZONA32024
CutterARIZONA32014
SahuaritaARIZONA32021
RuckerARIZONA32009
Forest LakesARIZONA22023
RedingtonARIZONA22007
Carr MtnARIZONA22024
Vicks PeakNEW-MEXICO22024
MagdalenaNEW-MEXICO22024
PomereneARIZONA12017
PatagoniaARIZONA12023
MaineARIZONA11997
Skull ValleyARIZONA12023
AmadoARIZONA12016
McnealARIZONA12024
Clay SpringARIZONA12024
PortalARIZONA11993
DragoonARIZONA12009

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