WAFWA Update - California
SHEEP STATS
JURISDICTIONAL WAFWA SUMMARIES PROVIDING IN-DEPTH, STATISTICAL SHEEP INFORMATION.
Desert Bighorn Sheep
Population
California’s desert bighorn sheep metapopulation consists of 64 herd units spread across the state’s southern mountain ranges. This metapopulation is managed in two distinct segments. The bighorn sheep in the peninsular ranges in the southwestern section of the metapopulation are considered a federally endangered distinct population segment and are therefore managed by a recovery plan drafted under the U.S. Fish & Wildlife Service (Map 1). All other desert bighorn sheep populations in the State are not considered endangered but have fully protected status except for individual bighorn sheep subject to sport hunting.California’s population was estimated at 5,000 desert bighorn sheep, though expert opinion suggests a decrease of ~10% (500 bighorn, such that 4,500 remain) over the past three years, attributed to impacts of drought and disease on recruitment. Among the populations in the 10 hunt zones (where population monitoring was most intensive outside of the peninsular ranges), population recruitment and overall health remained variable. The population in the Marble Mountains in the central Mojave was strikingly estimated to have zero percent recruitment during the last two years. However, data suggests the population on Old Dad Mountain in the central Mojave maintained healthy recruitment levels throughout the drought. Fortunately, heavy monsoonal moisture in the summer and fall of 2022, as well as significant to historic rainfall in the winter of 2023, has substantially decreased the drought severity throughout bighorn range. We anticipate higher levels of recruitment among most bighorn populations this season.
MAP 1
Bighorn sheep in California. The desert and Sierra Nevada subspecies are found in California. The desert subspecies is managed in two distinct population segments as seen above.
Licenses and Harvest
Per California Fish & Game Code, hunting of bighorn sheep in California is limited to rams. The California Fish & Game Commission may not adopt regulations authorizing the hunting in a single year of more than 15 percent of the mature rams (Class III or IV) in a single management unit. Hunts usually have a near 100% success rate except in the high-altitude White Mountain Hunt Zone 7. The 2023/2024 hunt season consists of 26 hunt tags (Figure 2 below).| ZONE | DETAILS | NO. OF TAGS |
| ZONE 1 | Marble/Clipper Mountains – General Method - Ram | 1 |
| ZONE 2 | Old Dad and Kelso Peak Mountains - General Method - Ram | 1 |
| ZONE 3 | Clark and Kingston Mountain Ranges - General Method - Ram | 4 |
| ZONE 4 | Orocopia Mountains - General Mthod - Ram | 1 |
| ZONE 7 | White Mountains - General Method - Ram | 6 |
| ZONE 8 | South Bristol Mountains - General Method - Ram | 2 |
| ZONE 9 | Cady Mountains - General Method - Ram | 2 |
| ZONE 10 | Newberry, Rodman, and Ord Mountains - Ram | 6 |
Number of general hunt tags offered in each hunt zone for the 2023/2024 hunt season. Twenty-three general tags, as well as 3 special fundraising tags are offered for the season.
Disease and Herd Health
Mycoplasma ovipneumoniae poses a significant threat to desert bighorn herds in California. Antibodies to the pathogen have been found in individuals from every herd unit tested in the State. Over the past decade, all age-class die-offs have been detected in the Old Dad, San Gorgonio, and South Bristol herds. Carcasses from the Old Dad herd sampled during the die-off tested positive for Mycoplasma. Carcasses from the San Gorgonio and South Bristol herds during their respective die-offs did not test positive for Mycoplasma; it is possible that the pneumonia in those herds was caused by a different, as-yet undetermined pathogen. No test and remove efforts have taken place in California.Connectivity
Historically, California’s desert bighorn sheep formed one large metapopulation. Three freeways (I-15, 40, and 10) have divided this metapopulation into six fragments as clearly shown by both genetic and movement data. Re-establishing genetic connectivity remains one of the top priorities for California’s desert bighorn sheep program. Construction is planned to start this year on three wildlife overcrossings traversing I-15 and a planned high speed rail line, designed specifically to benefit the species. WS— Danielle Glass, Environmental Scientist-California Department of Fish & Wildlife
