EFFECTS OF RELATEDNESS, DOMINANCE, AGE, AND ASSOCIATION ON RECIPROCALALLOGROOMING BY CAPTIVE IMPALA

Wild impala display a highly reciprocal allogrooming system that, by v irtue of its frequency and high degree of reciprocity, is unique among ungulates. A herd of 35 free-ranging captive impala provided opportun ity to examine the degree of reciprocity of allogrooming exchanges and the influence of relatedness, dominance, age and association on partn er preferences and distribution of grooming between allogrooming partn ers. As in wild impala, the exchange of allogrooming bouts in the capt ive impala was highly reciprocal regardless of partners. Kinship and d ominance had no influence on partner preference or distribution of gro oming between partners. Although mothers showed a significant preferen ce to allogroom with their unweaned offspring, this preference practic ally disappeared with older offspring. Age-mates (no greater than 6 mo apart) tended to associate with one another and spatial proximity was positively correlated with grooming partner preference. It was not cl ear whether impala actively sought out age-mates for grooming, or rand omly chose grooming partners from nearby age-mates. The failure to fin d a role for kinship and dominance is counter to what has generally be en found in most Old World terrestrial primate studies. The absence of pronounced social influences, coupled with the known effectiveness of grooming in removing ectoparasites, suggest that a utilitarian role, especially removal of ticks, is an important function of the impala re ciprocal allogrooming system.