A fence built on the Arizona and Mexico border in efforts to keep undocumented immigrants from entering Arizona, has had some unexpected consequences on wildlife. That fence has also affected the migrating black bears of Arizona, and may put stress on their population.
The black bears that are near the border have been recently studied and written about in the Biological Conservation . The bears in the area are not able to migrate into Mexico, and are faced with the threat of urban sprawl, highways and change of their migratory pattern.
Black bear population towards the border is at a much lower density than bears in the northern part of Arizona. The border is a unique region, from a biological point of view, researchers say, with many North American species reaching the southern limit of their distribution there and many South American species extending not much farther north.
The authors that wrote the paper on the black bears in the area would like to work with homeland security on measures that would help bears and other migratory land animals in the area. From The New York Times .