Reciprocal Allogrooming in Dam‐reared and Hand‐reared Impala Fawns

Abstract

AbstractAmong adult females and males of African antelope impala are unique in their performance of reciprocal allogrooming. The occurrence of this behaviour in neonatal impala fawns was explored in a free‐ranging impala herd at the San Diego Wild Animal Park where 5 dam‐reared fawns were observed from birth through 10 weeks of age. One‐way maternal grooming and reciprocal allogrooming with the dam and non dam partners emerged as distinct behavioural systems. Maternal grooming, directed mostly to the anogenital area, was typical of that seen in other ungulates, and sharply declined over the first two weeks. Reciprocal allogrooming, characterized by alternate exchanges of grooming bouts with a partner in the same manner as in adults, was seen as early as 3–8 d after birth. All fawns were grooming with unrelated adult females by the end of the second week. By week 2 virtually every measure of reciprocal allogrooming by fawns (grooming delivered per hour, reciprocity, and percent of encounters initiated) was as high as for adults. The appearance of this reciprocal allogrooming pattern, especially at such an early age, appears to be unique among ungulates, and possibly mammals in general. Three hand‐reared impala fawns, deprived of the opportunity to interact with older herdmates, but having access to impala fawns and heterospecific fawns, were observed from 1–3 mo of age. The hand‐reared impala showed no alteration in the occurrence of reciprocal allogrooming behaviour compared with the dam‐reared control fawns, indicating that allogrooming experience with older animals was not required for the appearance of reciprocal allogrooming at an early age. Interestingly, hand‐reared fawns persisted in grooming heterospecific fawns despite the fact that heterospecifics rarely reciprocated grooming. We postulate that the strong predisposition for impala young to groom others may be related to the threat of tick infestation in the impala's ecotone habitat.