Texas Released 31 Barbary Sheep in 1957. Now More Than 20,000 Threaten Native Wildlife
In 1957, the Texas Parks and Wildlife Department released 31 aoudad, also known as Barbary sheep, in the Texas Panhandle to increase hunting opportunities. An additional 40 animals were released the following year. The goal was simple: create a new hunting resource on the Texas range.
That initial introduction of 71 animals has since exploded into a population of more than 20,000 — and the species is now rapidly expanding and threatening native wildlife, particularly desert bighorn sheep, through competition and the spread of disease, according to TPWD officials.
20,000 Invaders vs. 730 Natives
Aoudad have expanded from the Panhandle into West Texas, including the Trans-Pecos region, where they now share habitat with native desert bighorn sheep. TPWD surveys in 2025 recorded approximately 730 desert bighorn sheep statewide — far fewer than the more than 20,000 aoudad roaming the same landscape.
The size of that gap is driven by two forces. Aoudad compete with native sheep for forage, pressing bighorns out of resources they need to survive. And the aoudad have a commanding reproductive advantage. Wildlife officials say aoudad often produce twins twice a year, while desert bighorn sheep typically have one offspring annually. That difference compounds relentlessly over generations, giving the invasive species a demographic edge that bighorn herds simply cannot match.
A Pneumonia Crash
In 2019, desert bighorn sheep in West Texas were impacted by a pneumonia outbreak linked to the pathogen Mycoplasma ovipneumoniae. Researchers have identified aoudad as potential carriers of the disease, often without showing symptoms.
The impact on bighorn numbers was severe. According to TPWD data, the desert bighorn population dropped from about 1,500 animals in 2019 to fewer than 500 by 2024. In roughly five years, the native population lost about two-thirds of its statewide numbers — while the aoudad population continued to grow across the same region.
By 2025, TPWD surveys recorded approximately 730 desert bighorn sheep. The population remains far below its pre-outbreak level and is still vastly outnumbered by the invasive aoudad sharing the same terrain.
Now Pinkeye Is Spreading
A separate disease, infectious keratoconjunctivitis — known as IKC, or pinkeye — is now 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.”
TPWD 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.”
The agency 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.”
TPWD has not documented IKC cases in desert bighorn sheep but is monitoring closely due to the potential risk. Given how the two species share habitat across the Trans-Pecos, wildlife managers are watching to see whether pinkeye jumps from aoudad to bighorns. For a population already weakened by years of pneumonia and decline, a new highly contagious eye infection could compound an already dire situation.
Helicopters and Open Season
To manage the growing aoudad population, Texas enacted Texas Senate Bill 1245, which took effect on Sept. 1, 2025. The law allows aerial hunting of aoudad from helicopters on private land.
That carries particular weight in Texas, where more than 93% of land is privately owned. Aoudad, classified as an exotic species, already have no closed season or bag limit on private property. The new law adds helicopter hunting to that existing framework, giving landowners and hunters another tool to reduce the invasive population from above.
TPWD is also managing aoudad populations through public land hunts and working with research partners, including Texas A&M University and Borderlands Research Institute, to study disease transmission and develop population control strategies.
This article was created by content specialists using various tools, including AI.
