Abstract - Agonistic Behavior of Territorial Pronghorn Bucks
Kitchen, David W. and Bromley, Peter T. 1974. Agonistic Behavior of Territorial Pronghorn Bucks. The Behavior of Ungulates and its realtion to management. pp. 365-381.
Paper No. 18 : Territorial behavior of pronghorn (Antilocapra americana Ord) bucks was observed independently for six summers, five rutting seasons, and one full winter and spring at the National Bison Range, Moiese, Montana, and Wind Cave National Park, Hot Springs, South Dakota. Pronghorn bucks were territorial from late March until early October and during this time they drove other males from their territories. Five basic phases were involved in territorial encounters: (1) stare at intruder, (2) vocal display of the territorial buck's presence with a snort-wheeze call, (3) approach intruder, (4) interact with intruder, and (5) chase or withdraw of intruder from the area. Phases may be omitted from an encounter or the encounter may terminate at any point. Occaisionally snort-wheeze vocalizations were sufficient to drive an intruder from the territory, particularly yearlings. The call seems to function as a display of activated male dominance and not territorial advertisement per se. A territorial buck's rate of approach (walk or run) was dictated by the age and social position of the intruding male and how deeply the interloper had penetrated the area. Behavior during an approach was highly variable and again depended on the aforementioned factors. Interaction phases were variable and no two were alike, but a general pattern of feed-thrash-mark-walk-threaten was noted in some encounters. Some of the variability seemed to be due to the same factors that regulated the territorial male's rate of approach. Chases were the most frequent manner in which territorial encounters ended. Eleven chasses crossed territorial boundaries and resulted in dominance reversals. Chases were more frequent in encounters with bucks low in the social hierarchy than with those in higher positions. Serious fights wer rare in the pronghorn, but did occur at times. Fighting behavior and skin defenses in the pronghorn are described, and it is noted that they fit the predictions of Geist's (1966) theory based on the horn morphology of the pronghorn. Some comparisions are made between the territorial systems of the true antelopes in the family Bovidae and that of the pronghorn.