One of the more than 30 Desert bighorn sheep released Nov. 18 to the Santa Catalina Mountains was found dead Wednesday by Arizona Game and Fish Department staff along the eastern edge of Sutherland Ridge near the headwaters of Romero Canyon.
The discovery was made after a mortality signal from the sheep’s GPS radio collar was detected during an aerial survey. All but one of the bighorn sheep were fitted with the collars.
What caused the death of the 4-year-old ram, captured Nov. 16 in the Trigo Mountains near Yuma, is currently under investigation. Samples were collected from the carcass for analysis.
Possible causes are injuries that may have occurred during or after capture, including myopathy or acute acidosis cause by stress that can lead to heart failure. Other possible causes are a fall, a predator or disease.
Toxicology results from the ram are expected by Friday, Dec. 6, or early the following week. “Any time we undertake a translocation of wildlife, mortalities are to be expected,” said Regional Supervisor Raul Vega of Game and Fish in Tucson. “Our intent is to minimize mortalities within this population by all available means.”
Since being released approximately one mile up the Romero Canyon Trail at Catalina State Park, the bighorn sheep have dispersed in the mountains from near Biosphere 2 to the west branch of Sabino Canyon, with most located in and around Pusch Ridge, their historic range.
The dead ram was one of six adult males released. The population includes 24 ewes and one yearling ram.
The overall objective of the Santa Catalina Bighorn Sheep Restoration Project is to restore a healthy, viable and self-sustaining bighorn sheep population that coexists in natural balance with a healthy native predator population in a naturally functioning ecosystem.