Resource Management

New Mexico Fire District Crew being observed / M. Weisenberger, USFWS

Refuge managers and wildlife biologists depend upon and utilize various tools to manage San Andres National Wildlife Refuge for the benefit of wildlife.

This relatively undisturbed refuge provides ideal opportunities to study and monitor wildlife to better understand their needs, and to be alert to possible declines in response to climate change and other challenges. Research projects include mountain lion, desert bighorn sheep and mule deer studies; prescribed burn effects; inventories of the rich array of insects; and bird banding efforts to learn more about species’ movement, survival and behavior.

Prescribed Burning
San Andres National Wildlife Refuge has an aggressive prescribed burning program to improve habitat for desert bighorn sheep and mule deer. The purpose of the prescribed burn program is to mimic historic fire occurrence, which has been altered due to grazing by livestock and long term fire suppression. The refuge’s prescribed fires are typically conducted in early to mid-June when humidity is the lowest and temperatures are the hottest. The objective of these burns is to reduce woody vegetation such as junipers that are moving into former grasslands.

The fires not only reduce the amount of woody vegetation, they recycle nutrients into the soil, and improve the nutritional value of plants that desert bighorn sheep and mule deer eat. Over time, plants such as mountain mahogany grow large and tall, become woodier with large branches and stems, and become decadent. This means the plant is essentially of no value to bighorn and deer and by burning these plants, the woody part of the plant is eliminated and the roots send up sprouts that contain more nutrients and are easier for the animals to feed on.

All of these plants and animals have evolved with fire. The refuge has been conducting prescribed burns since 1999 and has treated about 47,000 acres.

Protecting Native Species
An invasive plant or animal is not native to an area where it has become established and presents many problems for native plants and wildlife. Because they did not evolve here and have no predators, invasive plants and animals are able to rapidly expand in population size and eventually crowd out native species. At San Andres National Wildlife Refuge, two invasive species are especially problematic.

Salt cedar (Tamarix chinensis) is a tree that is actually from Central Asia. This plant was introduced into the western United States for erosion control in the early 1900’s and has spread throughout the western United States. It has established in large areas where it has completely eliminated all other trees. On the refuge, it is found primarily along springs and streams. It uses large amounts of water and will take over a spring to the point that the surface water often disappears. To combat it, refuge staff cut the trees and applies an herbicide.

Gemsbok or oryx (Oryx gazella) is an antelope native to southern Africa that was released on White Sands Missile Range in the late 1960’s. This large mammal has adapted extremely well to the area and has grown in numbers since its release. Concerns regarding oryx relate to the possibility of transmitting disease to native desert bighorn sheep and mule deer, and habitat damage due to trailing and feeding in sensitive riparian corridors. Various federal agencies that manage public lands within the Tularosa Basin are currently trying to reduce the oryx population by conducting hunts in cooperation with the New Mexico Department of Game and Fish.