FERAL ASS OR BURRO*
Equus asinus Linnaeus 1758

Order Perissodactyla : Family Equidae

*Introduced species

The feral ass or burro is not native to Texas and apparently only recently invaded Big Bend Ranch State Park from Mexico and neighboring ranches. Populations of feral asses are fairly common over the desert regions of the southwestern United States, and they are becoming established in far West Texas. In 1997 Frank Yancey (Texas Tech University) reported sighting a single individual in Presidio County, between Alamito Creek and the Cienega Mountains of Big Bend Ranch State Park. More recently, Fred Stangl of Midwestern University reported a small group of 8–10 individuals on property that straddles the Brewster–Presidio county line. Other groups of feral asses are known from along the Rio Grande from Candelaria, south and east to Black Gap Wildlife Management Area, including Big Bend National Park. A somewhat larger herd (>50 individuals) is known to inhabit the southern reaches of Big Bend Ranch State Park.

The establishment of these animals is potentially a major problem because they can become a destructive menace. Springs and creeks are being fouled by burro droppings in a landscape where water is limited and precious. Burros also compete with native wildlife for limited forage, decreasing available food sources for some animals, disrupting the food chain for other species, and threatening native plants.

Big Bend Ranch State Park is one of the major sites selected for the reintroduction of bighorn sheep, and burros are known to adversely affect desert bighorns via competition and disease transmission. In 2008 TPWD began to remove the burros by shooting them, and a public outcry ensued. The removal program was stopped, and TPWD is now seeking nonlethal options to removing the burros.

The same problem has been in place for several decades in nearby Big Bend National Park. The government is prevented from shooting the burros in the park and instead must capture and place them in adoption programs.

 

From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.