Agencies Seek Bighorn Sheep "Killers"
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Anza-Borrego Desert State Park continues to monitor the status of its most
famous inhabitants -peninsular bighorn sheep-in hopes of determining and
controlling whatever is causing part of that population to decline. "It's been
elusive because they are not in captivity," Anza-Borrego Naturalist Mark
Jorgensen said. "It's hard to get a good cross-section of an animal's health
when it's out running around." The peninsular bighorn sheep is in decline in the Santa Rosa Mountains and the Carizzo Cyn area, and is "holding its own" in Coyote, Palm and Tub canyons. Viruses are the suspected culprit in the decline of the animals in southern Anza-Borrego, and research continues into that possibility. "All arrows point toward several viruses combining to contribute to lamb mortality and declining population." Out of 1,000 blood samples taken statewide from the three subspecies of bighorn found in California (Nelson's, California and peninsular), the only area showing two or more viruses was southern Anza-Borrego, Jorgensen said. "The rest of the state is doing quite well," The 22nd consecutive bighorn sheep count in northern |
Anza-Borrego is scheduled for July 3-5, when about 60 volunteers will stake out
watering sites and record all bighorn they see. Jorgensen believes he has more
than enough volunteers for the count. In May Anza-Borrego participated in a census of bighorn in Carrizo Gorge as part of an ongoing cooper- active study of bighorn in southern Anza-Borrego with the San Diego Zoo and Wild Animal Park, Dept of Fish and Game and Univ of CA at Davis. Some funds for the study come from the environmental license plate fund, Jorgensen said. 10 sheep-two lambs, seven ewes, and a two-year old ram-were seen, Jorgensen said. One "freshly dead" ram lamb was found, but the cause of death was uncertain, and the carcass was not carried out of its remote location. "If we could have taken a cross-section of the lung, we could have found what it died of." The goal of the walking count was to determine the number of lambs so that figure can be compared with an end-of-season census. In the cooperative study, now in its 2nd year, four counts have been conducted to date. Radio telemetry collars, paid for by the Anza-Borrego Desert Natural History |
Assoc,
have been put on 10 sheep for monitoring by the Anza Borrego patrol plane.
Blood samples have been taken from some animals and studied. Five of the bighorn seen on the recent count wore collars, Jorgensen said. The US Fish and Wildlife Service is now becoming involved with the peninsular bighorn, and is pushing to have the animal listed as an endangered species, Jorgensen said. If it is listed, Fish and Wildlife will be the lead agency in the further study required. "We hope as a team to solve the problem," Jorgensen said. "By ourselves, we could not solve the problem. We can do land management, vehicle restrictions and feral cattle removal, but we need help-more assistance and money." A "major" interagency meeting will take place in early June to discuss the designation of peninsular bighorn as an official subspecies, and its federal listing, among other topics. The BLM, the Bighorn Institute, state Fish and Game, federal Fish and Wildlife Service, UC Davis and Anza-Borrego will participate in the forum. (From the Borrego Sun, Borrego Springs 6-4-92) Contributed by Gail Hanna. |