The Exotic Burro burros Equus asinus also called donkey or ass in the horse family ( Equidae ) Females are called jennies, and males are called jacks. characteristics include long ears and a short mane stands less than 5 feet at the shoulder Average weight is 400 pounds.
What’s a nice burro like you
doing in a desert like this?
The feral burros now found in the North American deserts are originally descended from the Nubian and Somali African wild ass. These animals have been domesticated in Africa since about 4000 BCE because of their hardiness and load-bearing capacity. All equines had vanished from North America at the end of the Pleistocene, but Spanish explorers reintroduced horses and burros (Spanish for ‘donkey’) to the continent in the 1500s. Burros were again used as pack animals in the western United States during the gold rushes of the 1800s and the subsequent Westward Expansion. Most of the burros currently living in the desert southwest are descendants of burros who escaped from or were released by their owners during this time. Consequently, some wild horse and burro advocates feel that these animals are an important element of the folklore and cultural history of the West.
1976-- an estimated 3,400 burros live in California.
Currently, approximately 7,000 burros live in CA, AZ, and NV.
Burros in the Desert Southwest
1997-- approximately 1,650 burros live in the Mojave National Preserve.
1993-- an approximate total of 7,500 burros live on BLM lands.
Yes, burros are exotic to the North American deserts. They occur as a species only because humans introduced them to the area. Without this introduction, burros would not have
naturally evolved in North America.
This is important in environmental policy-
making because burros must be
considered as unnatural elements of the
desert ecosystem. The native species of
the desert have been affected, for better or worse, by the introduction of burros, and the current managers must decide how to achieve an ecological balance with or without the burro.
Burros’ Effects on the
Because of their suitability to the desert environment in the Southwest, burros have thrived to the point of damaging the natural ecosystem. They have been accused of harming native species and degrading the physical environment. Burros put a severe drain on desert resources, as an adult may eat 6,000 pounds of vegetation per year (17 pounds per day) and drink 2,000 gallons of water per year.
… environmental effects
Resourceful foragers and digesters that they are, burros can have a great impact on the sparse vegetation of the desert. When foraging, a near-constant activity, burros crop the grasses and shrubs down to the roots. This not only damages the native vegetation, but also destroys food and habitat for other species.
One of the most often cited desert rivals of the burro is the bighorn sheep. In most cases, these two species are in direct competition over territory, food, and water. Burros are able to compete extremely successfully because of their enhanced ability to digest woody plants and other desert survival capabilities. Burros have also been accused of fouling water holes and being highly aggressive, thereby driving bighorns from their natural range.
A desert species of special concern is the desert tortoise. Although it may not seem obvious at first, burros have a severe negative impact on these threatened reptiles. Burros disrupt the tortoise’s habitat and eat some of their most important foods. Specifically, burros eat certain high protein plants that are essential for tortoise reproduction rates. The U.S. Fish and Wildlife Desert Tortoise Recovery Plan lists the removal of burros from tortoise habitat as necessary for the management of tortoise populations.
more and more burros…
The burros in the desert southwest would not be considered such a problem if their numbers were lower. However, burros are generally considered to be ‘prolific’ breeders, and annual growth rates range from 11-29%. Their populations simply continue to balloon because of a lack of natural controls, such as disease and predation. The two natural predators of burros in the desert, mountain lions and coyotes, are ineffective controls. So, most colts reach maturity and may live up to 25 or 30 years.
Wild and Free-Roaming Horse and Burro Act
Federal Law 92-195 passed in 1971
Capture and Adoption Programs
The most widespread form of burro control since the 1971 Act has been capture and adoption.
Methods of capture include helicopter herding and water enticement
After capture, animals are transported to BLM adoption program facilities or to non-profit animal sanctuaries.
Capture and Adoption: Criticism
Burros in Death Valley and
the Mojave National Preserve
Death Valley-- Burros have been specifically targeted as responsible for the decline in bighorn numbers. Some contest the view that burros have driven bighorns from their original range, citing geologic evidence. It may be that burros prefer the Precambrian or Cambrian geology that bighorns never used because the bighorns stay to Paleozoic carbonate formations.
Mojave-- Of special concern here is the desert tortoise. In efforts to preserve the tortoise’s critical habitat, NPS’s ultimate goal is the complete removal of all burros from the Preserve.
The National Park Service administers both Death Valley and the Mojave and is not subject to the same Wild Horse and Burro regulations as the Bureau of Land Management.
Prior to the California Desert Protection Act, the lands of the current park and preserve were managed by the BLM, which had determined burro populations consistent with its policies.
The NPS has agreed to an interim policy of maintaining BLM determined populations until a new management program is devised.
Controlling Burros in the Mojave National Preserve
The NPS has been capturing burros and putting them up for adoption as it tries to eliminate them from the Preserve. In 1998, the NPS entered an agreement with The Fund for Animals, whereby the Fund assumes responsibility for the burros and cares for them at the Black Beauty Ranch in Texas.
Burros have gone from trusty pack animals to feral nuisances in their 400 year history in North America. The current challenge for policy-makers is to manage burro populations in order to protect the desert environment, while keeping in mind that it is not the burros’ fault that they are here and survive so successfully. Capture and adoption programs are one option that has worked. Hopefully, this success will continue, and burros will become less of a problem in the desert southwest.