Translocations
While natural colonizations are promising, we cannot expect the population to occupy all 12 herd units required for delisting without the added boost of translocations. Moving sheep from one herd unit to another is extremely helpful in overcoming natural barriers to movement and in augmenting population growth in struggling herds. The future of the Sierra Nevada bighorn sheep may depend on the success of DFW’s translocation efforts. During the 12 years since endangered species listing, DFW has implemented several translocations. In 2001 a ram was moved from Wheeler Ridge to the Mount Williamson herd unit to help track bighorn there, but he quickly moved south to the Mount Langley herd. In 2003, two rams from Wheeler Ridge were added to the Mount Warren herd to boost genetic diversity. In 2005, five pregnant ewes were translocated from Wheeler Ridge to the Mount Baxter herd to expedite recovery, but three moved north to the Sawmill Canyon herd. In March 2009, six pregnant ewes were moved to Lundy Canyon from Mount Langley and Wheeler Ridge, and five of the lambs born survived through the summer and were yearlings in spring 2010.
Translocations will be essential to establish bighorn herds in the Kern Recovery Unit, an area of two herd units on the west side of the Kern River Canyon which sheep could not access on their own. This geographically-isolated population will be important as a reserve stock in the event that a disease epidemic spreads through the herds on the east side of the Sierra Crest. The Sierra Nevada Bighorn Sheep Foundation hopes to offer DFW financial support to offset the high cost of these translocations.