Social Behavior of Elk, Cervus Canadensis Nelsoni, in the Jackson Hole Area of Wyoming

The social life of the North American elk, Cervus canadensis nelsoni, was studied in the Jackson Hole Wildlife Park and in the adjoining wilderness territory. The research was sponsored by the New York Zoological Society and covered four summer seasons from 1948-51. The main method of observation was by stalking or by using blinds. It was found that climatic and seasonal factors modified the daily routine of herd-life. Definite patterns of herd structure and movement were found to exist. In contrast to other herd-forming mammals (sheep, cattle, buffalos, horses), the elk had a tendency in case of disturbance to break through a driving force. The segregation of groups by sex, into bull group and cow-nursery groups was shown. The changes in group structure in travel, grazing, crossing obstacles and in flight were described. A diurnal schedule of action for the elk groups showed regularity. Play-activity of elk-calves and their interaction with the herd followed definite patterns. The dominant-subordinate behavior of elk within the cow-herd and within the bull-group manifested little violence but was firmly established. Leadership by mature elk cows existed in the majority of observed situations. Group changes with the approach of the rutting season in August and September led to the gradual dissolving of the bull-elk groups during the velvet-rubbing stage (August), and to the joining of bulls with existing cow-elk groups. The full emergence of the rutting season in September with cold spells providing stimulation for bugling and sex-activity was noted. The behavior of the free-ranging elk of the Jackson Hole herd was observed while the elk were still on the winter-feeding grounds of the Elk Refuge; the formation of sub-groups took place within the Refuge weeks before actual migration. The subgroups sometimes broke into smaller and very small (3 to 5 elk) units, proceeded along the water runs toward higher locations outside of the Refuge. The onset of the calving season changed the group composition, delaying the cows and some of their yearlings. Groups of males and some non-bred females moved on to higher altitudes in the wilderness areas. Relations and interactions of cows and calves and establishment of calf pools on a cooperative basis were noted. Female bugling, defense reactions and the displacement of yearlings was shown. The elk groups under stress of disturbances (highway with traffic) and natural obstacles (river crossings) showed integrated action. Male groups arrived early on high summer ranges, still covered with snow. Gradual arrival of nursery groups through main routes of migration. Adaptation to the cold climate and abundant pasture changed schedule of daily activity completely. Besides pasturing, the elk spent much time and energy in play, bathing and wallowing. Vocal communications were frequent and conspicuous. Bugling of males while still in velvet was commonly heard. Group formation was found to be loosely defined. Aggregations of several hundred elk were frequently seen but also medium and small elk bands were found. Flight distance was lowest ever encountered. Elk were bold, not nervous and in prime condition by midsummer. Contrast to normal elk behavior on summer ranges was shown by groups of elk on poor habitat. Their schedule of activity from dusk to dawn was interrupted by a period of rest and rumination during the hot midday. Poor grazing caused the animals to look shaggy and to show nervous disposition indicated by an extremely high object-flight-distance. No playful activity was detected. Grazing and fly-fighting occupied a large proportion of their time. Group organization was constant with leadership by mature females.