Habitat Management

Habitat Types
Buenos Aires National Wildlife Refuge contains 117,354 acres in the Altar Valley of southern Arizona. Most of the acreage is semidesert grassland. At the eastern end of the refuge are several riparian (wetland or stream) areas. These include Arivaca Cienega, which is a spring-fed marsh, and the seasonal Arivaca Creek. At the west end of the refuge is Brown Canyon, in the lower reaches of the Baboquivari Mountains. Here a sycamore-lined stream meanders through oak woodland.

Habitat Restoration
An important objective of the Refuge is to protect and restore the three habitat types. Protection and restoration benefits the native animal species, with particular emphasis on habitat quality for masked bobwhite. Habitat management is guided by the Refuge-wide Habitat Management Plan which helps determine the best strategies to use in the field to achieve the preferred habitat conditions for variety of designated species. A variety of habitat management strategies will be implemented to improve habitat conditions for both endangered and non-endangered species.

Prescribed Burning
Historic records indicate that this formerly open grassland was maintained with natural fires caused by lightning during the summer monsoon season. Fire size and frequency declined after 1882, probably as a result of habitat degradation. Through the last century the grassland has been invaded by mesquite trees and other shrubby vegetation. Grassland or prairie ecosystems require fire to keep shrubs and trees from invading the landscape. The Refuge uses prescribed burning, in conjunction with other habitat management strategies, to inhibit the growth and spread of mesquite trees and to remove small shrubs called snakeweed and burroweed. Fires return nutrients from burned plant material into the soil to nourish new grass. Fire benefits the wildlife by restoring native grasses and stimulating the growth of important food plants. For additional information on fire visit
Fire Website: http://www.fws.gov/fire/

Revegetation
The refuge is attempting to control the amount of Lehmann's lovegrass, a South African grass planted in the 1970's to control erosion. This exotic species now dominates the landscape, replacing native grasses. A planned second stage of restoration is to revegetate with native grasses through seeding projects.

Erosion Control
Loss of grass cover has led to erosion with loss of topsoil. The Refuge hopes to stabilize the banks of washes and roads by partnering with local landowners to install some erosion control structures throughout the entire Altar Valley.

Water
The Refuge maintains existing stock ponds left over from ranching days and has also constructed several new water impoundments. These structures catch natural rain runoff. As the water table in the Valley drops through human use, water sites are increasingly valuable to wildlife in this dry environment.

Fence Removal
The Refuge is removing or altering barbed wire fences left over from ranching days. This aids the movement of deer and pronghorn. Many volunteers and wildlife organizations assist the refuge in many of the fence removal projects.

Southwest Region 2 Refuges | National Wildlife Refuge System | USFWS National Site