Buenos Aires National Wildlife Refuge

Buenos Aires National Wildlife Refuge (Buenos Aires NWR) provides 117107 acre of habitat for threatened and endangered plants and animals. This refuge, in Pima County, Arizona, was established in 1985.

Natural history
The semidesert grassland supports the reintroduction of Masked quail and pronghorns. Prescribed and natural fires play a major role in maintaining and restoring the sea of grass that once filled the Altar Valley. Riparian (wetland) areas along Arivaca Cienega and Arivaca Creek attract an abundance of birds. Brown Canyon, to the west of the Arivaca Creek area, is nestled in the Baboquivari Mountains, where a sycamore-lined stream meanders through oak woodland.

Fauna
The refuge is home to 58 mammal species. Among the larger species are mule deer, white-tailed deer, pronghorn, javelina and puma. There are also more than 325 different bird species and 53 species of reptiles and amphibians. Reintroduced masked bobwhite (Colinus virginianus ridgwayi) are found in the refuge.

Occasional jaguar vagrants are reported in the area, which is contiguous with Mexico. Between 2004 and 2007 an old male jaguar was followed by researchers in the area. The animal was called 'Macho B' by the researchers and has been previously photographed in 1996 in the area. During the study its home range compassed the mountains to east and west of the Altar Valley, which is situated in the Refuge. In addition at least one other jaguar was recorded in the area during that study.

The male jaguar, 'Macho B', is dead. The jaguar was euthanized after being captured on a snare trap.

Access
Most of the Buenos Aires National Wildlife Refuge is open for visiting and research. Guided access is also available through Friends of Buenos Aires NWR programs.

Some 3500 acre of the refuge (about 3% of its area) was closed in 2006 to public access due to human safety concerns. At that time there was a marked increase in violence along the border due to human and drug trafficking. The closed area extends north from the international border roughly 3/4 mi away. As of 2010, this portion remains closed; however, the Fish and Wildlife Service reports a marked decline in violence.

Environmental degradation is the most visible consequence of border crossings through the refuge. A few years ago, there were 45 abandoned cars on the Buenos Aires refuge near Sasabe, Arizona and enough trash that a volunteer couple filled 723 large bags with 18000 lbs of garbage over two months in 2002.