From an important op-ed in the San Diego Union Tribune
The southern border region is one of the most bio-diverse areas in the United States and a crossroads for many carnivores. Today, the area is more widely known for the highly charged border politics involving people than for how those politics may affects the bears, jaguars, mountain lions and other wildlife that make the area home.
Safe Passages, an important book on road-wildlife issues.
For hundreds of years, as national borders have been redrawn by various governments, these species have maintained a natural distribution across the region. A recent study provided insight into the critical role that movement corridors – the paths that wildlife follow to access seasonal resources such as various foods, water and mating opportunities – play in ensuring the persistence of bears and other large carnivores in this region.
The collaborative study, by the Wildlife Conservation Society and federal and state land and wildlife management agency partners, found that bears in the southern United States are more closely related genetically to endangered black bear populations in northern Mexico than to those in central Arizona and New Mexico. These data suggest that bears and other carnivores are likely dependent upon cross-border corridors to travel between the naturally, patchily distributed habitat in the region.
Read more here.