• Jackrabbit densities on fair and good condition Chihuahuan desert range

      Daniel, A.; Holechek, J.; Valdez, R.; Tembo, A.; Saiwana, L.; Fusco, M.; Cardenas, M. (Society for Range Management, 1993-11-01)
      This study was conducted on Chihuahuan desert range near Las Cruces, in southcentral New Mexico, to determine the relationship of blacktailed jackrabbit (Lepus californicus) densities to good (GC) and fair (FC) range condition. The Soil Conservation Service procedure was used to classify ecological range condition. Line transect procedures were used to estimate jackrabbit populations from July 1988 to December 1990. Concurrently vegetation cover and mean plant height were determined with the line intercept procedure. Jackrabbit densities on the fair condition range were higher (P < 0.10) than those on the good condition range. This difference is attributed to the fair condition range containing more protective cover and preferred forage than good condition range. Jackrabbit abundance showed no season (P < 0.10) or year differences (P < 0.10). Jackrabbits preferred grass-shrub mosaic habitats more than shrubland and grassland habitats. The need for diverse food sources and protective cover were apparently major determinants of habitat selection by jackrabbits. The good condition range contained greater (P < 0.10) grass cover and less (P < 0.10) shrub cover than the fair condition range. Our results indicated that maintaining Chihuahuan desert ranges in good to excellent condition is the best means of achieving lower abundance of jackrabbit populations.
    • Jackrabbits

      McAdoo, J. Kent; Young, James A. (Society for Range Management, 1980-08-01)
    • Jackson Hole, Wyoming: A Summer Tradition Continues

      Samuel, Marilyn J. (Society for Range Management, 1986-02-01)
    • Jaguar and Puma Predation on Cattle Calves in Northeastern Sonora, Mexico

      Rosas-Rosas, Octavio C.; Bender, Louis C.; Valdez, Raul (Society for Range Management, 2008-09-01)
      Predation by jaguars (Panthera onca) and pumas (Puma concolor) is often a source of conflict with cattle ranching in northeastern Sonora, Mexico. Because jaguars are endangered in Mexico, such conflicts have biological, social, and economic consequences. We documented the extent of predation by jaguars and pumas on cattle in 1999-2004 in northeastern Sonora, where the northernmost breeding population of jaguars exists in North America. Jaguars and pumas killed only calves , 12 mo old, and calves constituted 58% of prey biomass consumed by jaguars and 9% by pumas. Annual cause-specific mortality rates of confirmed jaguar predation (< 0.018), confirmed and suspected jaguar predation (< 0.018), and all confirmed and suspected large felid predation (< 0.018) were low and cattle calf survival was high (0.89-0.98 annually). If calves reported as missing but for which no evidence of mortality could be found were classed as large felid predation, annual cause-specific rates increased to 0.006-0.038. Collectively, confirmed jaguar and puma predation accounted for < 14% (57/408) of total cattle losses, with jaguars responsible for 14% of all calf losses; this could increase to a maximum of 36% (146/408) if missing calves were included in the totals. While jaguar and puma predation may have an impact on some small cattle operations, it is generally minor compared to losses from other causes in northeastern Sonora. Moreover, 91% of all confirmed calf kills were associated with three individual jaguars in our study. Targeting problem cats rather than broad-scale predator control may therefore be a viable alternative to address chronic predation problems. Because most (83%) instances of jaguar predation occurred during the dry season along thick riparian habitats, modified cattle husbandry operations, such as establishment of permanent water sources in uplands and away from dense vegetative cover, could ameliorate many cases of predation by jaguars on cattle. 
    • Jaguar Critical Habitat Designation Causes Concern for Southwestern Ranchers

      Svancara, Colleen M.; Lien, Aaron M.; Vanasco, Wendy T.; Lopez-Hoffman, Laura; Bonar, Scott A.; Ruyle, George B. (Society for Range Management, 2015-12-01)
      On the Ground • The designation of jaguar critical habitat in April 2014 in southern Arizona and southwestern New Mexico created concern for livestock ranchers in the region. • We interviewed ranchers to understand their concerns with the jaguar critical habitat designation and their attitudes toward jaguars, wildlife conservation, and resource management in general. • Ranchers we interviewed were concerned about direct impacts of designated critical habitat on ranching, as well as possible alternative agendas of critical habitat advocates and issues specific to the borderlands region. • The ranchers were less concerned about the presence of jaguars but were more concerned about possible limiting effects of the Endangered Species Act (ESA), distrust of government entities, and litigious environmental groups. • To maximize effectiveness, government agencies should work to foster trust in the ranching community, be cognizant of sensitive issues specific to the region that may challenge endangered species conservation goals, recognize the opportunity to work with ranchers for endangered species management, and provide outreach about implications of the ESA.
    • Japanese Brome Response to Atrazine in Combination With Nitrogen Fertilizer in the Mixed Prairie

      Hewlett, D. B.; Johnson, J. R.; Butterfield, R. I.; Mosley, V. K. (Society for Range Management, 1981-01-01)
      Atrazine was used to control Japanese brome in conjunction with nitrogen fertilization to determine if herbage production could be increased more than by fertilization alone. Atrazine treatments included a single application, application in alternate years, and application for two or three consecutive years. Atrazine did not significantly increase production more than fertilizer alone and caused some decreases in western wheatgrass production at low rates of N in one year at one location. Unless atrazine was applied in two or more years, Japanese brome was a prevalent the second growing season after application as where it had never been controlled. Application of atrazine in consecutive years increased shortgrass production at one location.
    • Jarbidge Ranger District: It Can Be Done

      Timothy, Kenneth (Society for Range Management, 1980-08-01)
    • Jean Snider Schadler—A Woman in Range Management

      Turner, Sherry (Society for Range Management, 1984-02-01)
    • Joseph H. Robertson—Range Scientist Pioneer

      Davis, Barry (Society for Range Management, 1989-10-01)