How Aoudad Sheep Took Over Texas and Created a Wildlife Crisis Decades in the Making
In 1957, wildlife managers in Texas made what seemed like a straightforward call. They released 31 Barbary sheep — also called aoudad — into the Panhandle to increase hunting opportunities. The following year, they added 40 more.
Nearly seven decades later, that small introduction has become an ecological cascade. According to Texas Parks and Wildlife Department officials, the aoudad population has grown to more than 20,000 animals, spreading from the Panhandle into West Texas and the Trans-Pecos region — right into the territory of native desert bighorn sheep.
And the bighorns are losing.
A Lopsided Contest
TPWD surveys in 2025 recorded approximately 730 desert bighorn sheep statewide. Compare that to the more than 20,000 aoudad now roaming the same landscape.
The biology makes the imbalance worse. Aoudad reproduce far faster than bighorn sheep, often producing twins twice a year. Bighorn sheep typically have one offspring annually. That difference compounds over time. Aoudad also compete with native sheep for forage — the same grasses, shrubs and desert vegetation that bighorn sheep depend on.
The result is a species that arrived as a guest and now dominates the habitat of one of the state’s most recognizable native animals.
Disease Changes the Equation
Competition for food and space is one problem. Disease is another — and it has been devastating.
In 2019, desert bighorn sheep in West Texas were hit by a pneumonia outbreak linked to the pathogen Mycoplasma ovipneumoniae. Researchers identified aoudad as potential carriers of the disease, often without showing symptoms. An animal that looks perfectly healthy can still pass a lethal infection to its native neighbors.
The impact was severe. According to TPWD data, the desert bighorn population dropped from about 1,500 animals in 2019 to fewer than 500 by 2024 following the outbreak. In roughly five years, the population lost more than two-thirds of its numbers.
A New Disease Is Spreading
Now another illness is moving through the desert. Infectious keratoconjunctivitis — commonly known as pinkeye — is spreading among aoudad in West Texas.
TPWD reported, “Since December [2025], approximately 25 Aoudad showing severe clinical characteristics (e.g., blindness) in one or both eyes have been documented across 30 miles.”
The agency described the disease as “a highly contagious eye infection that can be a common disease in livestock. IKC has also been described in many wildlife species. It rarely affects just one animal, but spreads throughout a herd.” TPWD added it “can be spread by flies, dust, and other exposed environmental vectors. In wildlife populations there is no available treatment and the disease naturally runs its course through the herd.”
Pinkeye steals sight. For a sheep navigating rugged desert terrain, blindness is a death sentence in slow motion.
TPWD has not documented IKC cases in desert bighorn sheep but is monitoring closely due to potential risk. Given that researchers have already identified aoudad as potential carriers of pneumonia — often without showing symptoms — wildlife officials have reason to watch carefully.
Managing a Population That Keeps Growing
Texas is now trying to rein in the aoudad population it created. Texas Senate Bill 1245, which took effect on Sept. 1, 2025, allows aerial hunting of aoudad from helicopters on private land.
That legal change matters because of a key fact about Texas geography: more than 93% of land in the state is privately owned. Aoudad are classified as an exotic species and have no closed season or bag limit on private property, but reaching them across the vast, rugged ranches of West Texas has always been the practical challenge. Helicopter hunting addresses that.
TPWD is also managing populations through public land hunts and working with research partners, including Texas A&M University and Borderlands Research Institute, to study disease transmission and population control.
This article was created by content specialists using various tools, including AI.
