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

Black Vulture In Sierra Madre Occidental

All regionsSierra Madre OccidentalGeneralists

Black Vulture in Sierra Madre Occidental has surged: up 277% on the route-weighted index since 1997.

+277%Since 1997TrendPercent 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 →
3Routes 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 →
16YearsYears 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 →

Black Vulture has surged in Sierra Madre Occidental: up 277% on the route-weighted index since 1997.

Routes In Sierra Madre Occidental

Routes recording Black Vulture 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 →
PatagoniaARIZONA62023
Peña BlancaARIZONA12000
AmadoARIZONA12023

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