Dances with Sheep: Counting Bighorn in the Desert
Travel along with Anne Zuparko as she spends three days in Anza-Borrego Desert State Park.
The peninsular bighorn sheep—known for its unique ability to withstand extreme, harsh conditions—is a true symbol of the California desert wilderness. Like the terrain it inhabits, it’s both rugged and beautiful. The sheep moves with an agility that mirrors the desert’s sparse and breathtaking landscape. Skillfully maneuvering rocky desert outcroppings, the bighorn demonstrates exceptional grace that belies its powerful build and hallmark massive horns.
An Endangered Species
The iconic peninsular bighorn faces real threats to its long-term survival. The sheep were listed as a federally endangered population in 1998; there are now estimated to be only 875 living in the United States. Scientists point to several factors that may threaten bighorn sheep populations.
- Habitat Fragmentation. Bighorn reside in the peninsular mountain ranges from the San Jacinto Mountains to the southern tip of the Baja peninsula. The Coachella Valley and its adjacent mountains—a vital corridor for bighorn—are undergoing rapid population growth. Urban development here will displace sheep and other desert species if left unchecked.
- Predation by animals such as mountain lions, bobcats, coyotes and eagles.
- Disease. Bighorn are highly susceptible to diseases, especially pneumonia. Many domestic sheep, goats and other healthy animals carry bacteria that are fatal to bighorn. Contact with one goat can potentially devastate an entire range of sheep.
- Climate change. In lower elevations, rising temperatures could decrease the amount of vegetation available for sheep and the water levels in freshwater springs that they depend on for survival. This risk could worsen as the southwestern climate becomes drier and warmer.
Protecting Desert Creatures, Large and Small
The Conservancy and our partners collaborate to implement conservation strategies to protect this critical land and the animals that inhabit it.
- Conservancy staff often participate in the annual bighorn sheep count that occurs in Anza-Borrego Desert State Park. The data collected from this count are used to track and monitor changes in the bighorn sheep population.
- The Conservancy works with partners in San Diego County to expand and protect crucial desert land and species, including more than 4,000 acres of bighorn habitat in Anza-Borrego Desert State Park.
- Together with partners at Anza-Borrego Desert State Park, UC Davis and the Department of Fish and Game, the Conservancy is placing radio collars on sheep, mountain lions and deer in order to study their behavior.
Did You Know? Cool Facts about the Peninsular Bighorn Sheep
- Extreme eyesight. Bighorns see better than most mammals—their vision is about eight times more powerful than that of humans. They can spot a person walking in the desert more than a mile away.
- The battle of the horns. Rams often compete for ewes by participating in head-butting contests. They can charge each other at speeds of more than 20 mph, and when their horns crash it produces a sound that can be heard more than a mile away. These clashes may last as long as 20 hours!
- With rings come wisdom. The age of a bighorn can be determined by counting the rings on its horns—one year for each ring.
- Those hardheaded males. Male sheep horns can weigh as much as 30 pounds and can reach up to 33 inches long! Ewes’ horns typically max out at 8–10 inches in length.
- Girl power. Rams live an average of 9–12 years, while ewes edge them out with an average lifespan of 10–14 years.
- Lean machines. With compact and muscular bodies, mature rams in the peninsular ranges weigh more than 200 pounds; mature ewes weigh 105–130 pounds on average.
- They grow up fast! Young lambs can walk and climb as well as their mothers can within a day, and they remain with their mothers for the first year of their lives.