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

Western Screech-Owl In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Western Screech-Owl in Sierra Madre Occidental has collapsed: down 87% on the route-weighted index since 1989.

-87%Since 1989TrendPercent 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 →
7Routes 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 →
17YearsYears 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 declinecomputed 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 →

Western Screech-Owl has collapsed in Sierra Madre Occidental: down 87% on the route-weighted index since 1989.

Routes In Sierra Madre Occidental

Routes recording Western Screech-Owl in Sierra Madre Occidental.
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 →
SahuaritaARIZONA32008
San SimonARIZONA12024
Peña BlancaARIZONA12007
PatagoniaARIZONA11989
RedingtonARIZONA12009
SprucedaleARIZONA12012
MagdalenaNEW-MEXICO12009

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