• Circumstances Associated with Predation Rates on Sheep and Goats

      Nass, R. D.; Lynch, G.; Theade, J. (Society for Range Management, 1984-09-01)
      Factors possibly associated with high (over 5%) and low (0-5%) predation intensities were compared among 95 sheep or goat producers in 5 states to determine if important differences were evident between the 2 groups. Data were compared for the following variables: losses to predation, flock size, type of ranch operation, management practices, predator indices, prey indices, use of U.S. Animal Damage Control program, private control efforts, predation history, timing of predation, and presence of other sheep or goats nearby. Overall, 45% of the producers reported over 5% predation losses of their lambs or kids and predation percentages tended to increase with decreased flock sizes. Feeder lamb and range sheep operations had predominantly low predation loss percentages, but most operations that included goats reported over 5% predation losses due to goat predation. A variety of management practices were used by both groups; however, low loss producers indicated low natural prey and predator populations. Most of the producers used the federal ADC program and some type of private control effort, although more high loss producers used both types. Rough, bottom, and brush grazing lands, historic predation problems, and high predator indices characterized many of the high loss producers.
    • Electric fences for reducing sheep losses to predators

      Nass, R. D.; Theade, J. (Society for Range Management, 1988-05-01)
      The use of anti-predator electric fences for reducing predation on sheep was investigated by interviewing 101 sheep producers in the Pacific Northwest. Significant reductions in sheep losses to predators were reported after installation of electric fences compared to pre-fence losses. Low sheep losses to predation were also reported by those producers that acquired sheep after installation of electric fences. The expenses of construction and maintenance were important considerations in management plans; however, most producers were satisfied with electric fences for sheep containment and predator exclusion.
    • Mortality Associated with Sheep Operations in Idaho

      Nass, R. D. (Society for Range Management, 1977-07-01)
      Nine sheep bands from Idaho were monitored for mortality causes and circumstances during 1973 and 1974; two bands were monitored during 1975. Total ewe and lamb losses for the respective years were 9.5%, 11.5%, and 11.1%. Premature births, starvation, and disease were major causes of lamb deaths during the 3-month home ranch lambing period. During the same period, disease, shearing stress, infection, and birth complications were the main causes of ewe mortality. The yearly mean total loss for lambs on the range was 5.2%, the minimum (confirmed) loss to predators was 1.4%, and other known causes of death represented 1.1% loss. The mean minimum predation was adjusted to 2.9% on the basis of unaccounted for loss. The minimum predation rate on ewes was 1.1% (adjusted 1.6%) even though they were on the range twice as long as lambs. Coyotes accounted for 93% of all predator-killed lambs and ewes. Predation was most severe on lambs during the first 6 weeks on the range, but more ewes were killed during the fall and winter.
    • Sodium Monofluoroacetate (1080): Relation of Its Use to Predation on Livestock in Western National Forests, 1960-78

      Lynch, G. W.; Nass, R. D. (Society for Range Management, 1981-09-01)
      Concern over certain animal damage control methods used by the U.S. Fish and Wildlife Service (USFWS), primarily the predacide Compound 1080, prompted a Presidential Order in 1972 banning the use of toxicants on public lands. This continuing ban of 1080 use has been reinforced by the recent policy address issued by the Secretary of the Interior. Following the initial ban, greater emphasis was placed on aerial hunting of coyotes for prevention and correction of damage to sheep and goats. Aerial hunting is expensive, however, and has only limited application in timbered, mountainous areas of many national forests. In the period since toxicants were banned, number of grazing livestock reported as lost to predation on western national forests has increased. Numbers of toxic bait stations (1080) used throughout the West, from 1960 until the 1972 ban, showed a strong inverse relationship with numbers of livestock reported lost to predation on national forests during these same years.