The California bighorn sheep herd inhabiting NDOW hunt unit 012 occupies an expansive amount of habitat in the Calico Mountains, Little High Rock Canyon, High Rock Canyon, Pole Canyon, Chukar Gulch, Warm Springs Canyon, Trough Mountain, Mahogany Mountain, and Yellow Rock Canyon. Highest densities and concentrations of bighorns are located within wilderness boundaries near Little High Rock Canyon, High Rock Canyon, and in the Calico Mountains. These locations will be the areas of primary focus for the capture. According to NDOW, the removal of 20-35 sheep will not impact the herd and may help increase productivity in those where the highest densities of sheep are found. Based on recent recruitment rates, it is estimated that it will take one to two years for the herd to replace the animals removed. The removal of 20-35 animals represents a 10-15 percent reduction in the population.
Similarly to hunt unit 012, hunt units 032 and 034 may have similar activities occur within the Pahute Peak Wilderness, North Black Rock Range Wilderness, Lahontan Cutthroat Trout ISA WSA’s, and Pine Forest Wilderness/Blue Lakes WSA. According to NDOW, sheep will be captured in high density areas because there is a need for sheep to be released within low density areas.
NDOW proposes to conduct aerial surveys during the months of August and September to determine the status of bighorn populations and habitat conditions. Information obtained from these flights will be used to evaluate whether herds can sustain removals, and to determine how many animals can be removed through capture operations. NDOW proposes to land a helicopter in designated wilderness in order to capture and relocate 20-35 bighorn sheep. The sheep will be taken from areas of high population density and released in areas needing population supplementation. Capture operations will occur over approximately 2-4 days November through February.
NDOW contracts aerial net-gun capture services. The capture crew consists of a pilot and several members cross-trained in different aspects of large animal captures. The aircraft (MD500D or Bell 206 Long Ranger helicopter) is operated at altitudes generally below 300 feet above ground level while the crew attempts to locate animals, and in ferrying to and from a base of operations. In capture mode, the pilot maneuvers the aircraft close to ground level in pursuit of fleeing animals. The aircraft is maneuvered alongside an animal and at an opportune moment the pilot alters the lateral attitude of the aircraft presenting a larger target to the gunner.
Once an animal is entangled in a net the helicopter may hover close to the ground or land briefly to allow the handler(s) to dismount. A handler quickly works the animal out of the net, applies hobbles and a blindfold, and secures the animal in a transport bag. The transport bag is fastened to a sling line that is attached to the underside of the aircraft. Once captured, handled, and readied for transport, the sheep is ferried in a sling load fashion beneath the aircraft to the base of operations. Bases of operations or staging areas are confined to previously disturbed areas beyond wilderness boundaries.
The specific areas where the sheep will be released are unknown at this time. According to NDOW, all releases will not be in special designated areas. One or two releases may be in the Winnemucca District and the other may be in the Surprise District. BLM is undergoing the NEPA process because the proposed project is within Wilderness Study Areas. IM-NV-2004-043 requires NOPAs (Notice of Proposed Action) with a minimum 30 day public comment period. The deadline for the DNA is May 1st, 2013 to allow enough time for the NOPA.