Mammals

The Mammals of Rancho El Aribabi fills an important gap in the detailed knowledge of the diversity and abundance of the mammals in the Sky Island region of the U.S. and Mexico borderlands. The multiyear camera trapping effort captures a thorough inventory and baseline of this private protected area and conservation ranch in the heart of a migratory corridor that allows movement north and south in the high latitude portion of the Sierra Madre.

The status of beaver (Castor canadensis) in northeastern Sonora, Mexico, is uncertain. We surveyed the Cajon Bonito River to assess the beaver’s status and habitat and found five colonies. Limiting factors appear to be pollution due to animal waste, deforestation of riparian trees, and human exploitation. Beavers did not appear to require habitat diversity as much as dense riparian and aquatic vegetation in waters with low organic content. These kinds of studies are imperative to understanding the natural history and ecology of the species in this unique region.

We used data from eight years of camera trapping at Rancho El Aribabi, a cattle ranch and conservation property in northern Sonora, Mexico, to examine the ecology of the northern-most known breeding population of ocelots (Leopardus pardalis). Ocelots were found mostly in two discrete and disjunct areas: a riverine riparian canyon at just less than 1,000 masl elevation and along arroyos in an oak-mesquite savanna in the Sierra Azul at 1,266–1,406 masl.