Top marks from top dogs: tandem marking and pair bond advertisement in African wild dogs

Tandem marking occurs when both members of a pair scent-mark the same location in quick succession. This widespread behaviour, common in canids and monogamous antelopes, is generally believed to be involved in pair bond formation and advertisement. Despite their potential utility in determining tandem mark function, observations of individual contributions to tandem marking within pairs are rare. To this end, we made detailed observations of free-ranging dominant African wild dogs, Lycaon pictus, uncovering differences in the tandem-marking behaviour of pairs depending on their relatedness. In all packs, dominants were more likely to overmark their partner's scent mark than their own, but dominant-initiated scent marks were more likely to become tandem marks in related (full-sibling) pairs than in unrelated pairs. Despite this, females were more frequently on top at the end of marking bouts in related pairs than in unrelated pairs, because females in related pairs were more likely to overmark initial scent marks left by males, and less likely to have their scent marks subsequently overmarked by males. Scent-marking bout length was also significantly longer in related pairs. These differences suggest that advertising the presence of a mated dominant pair may be the main function of tandem marking in African wild dogs, but when mating opportunities are absent within the pack, contributions to tandem marking are altered, with individual advertisement perhaps becoming more important.