Genetic and behavioural evidence of monogamy in a mammal, Kirk's dik–dik (;Madoqua kirkii)

Abstract

Little is known about the mating behaviour of monogamous mammals. Here, we present behavioural and genetic evidence of fidelity in a socially monogamous dwarf antelope, Kirk's dik–dik. DNA microsatellite analysis revealed no evidence of extra–pair paternity (EPP) in dik–diks: mothers' partners matched the paternal genotype in all 12 juveniles tested. One likely reason for the absence of EPP is that males guard their mates closely during oestrus and over–mark all female scent, thereby reducing the likelihood of other males attempting to mate. In addition, males may be limited in their ability to search for extra–pair copulations (EPCs) by activities associated with pair–bond maintenance. Year–round, males maintained proximity within pairs, followed their female's activity patterns, and spent approximately 64 per cent of their time with their partners. However, males did attempt to obtain EPCs when the opportunity arose, and genetic monogamy in dik–diks is probably best explained by the behaviour of females: in contrast to many monogamous female birds, female dik–diks do not appear to seek EPC partners. We propose that females avoid extra–pair males because they are unable to mate with them without instigating a potentially dangerous conflict.