Reconstruction of parentage in a band of captive hamadryas baboons

The male leaders of free-ranging harem groups of hamadryas baboons are beli eved to mate exclusively with the female members of their harems, which typ ically contain no more than 2-3females. Using no-parent parentage exclusion analysis (PEA) we identified the paternity of 25 offspring born in a capti ve band of hamadryas baboons (Papio hamadryas hamadryas) containing five ad ult males, each with a stable harem of about five females. Nine of 13 micro satellite (SSR) loci known to be highly polymorphic in rhesus macaques (Mac aca mulatta) were successful in identifying the sires of all but two offspr ing without knowledge of the dams' genotypes, and we were able to determine the sires of all offspring when the dams' genotypes were considered. Matin g success of the males ranged between 2 and 7 offspring and bore no clear r elationship to the males' ages, ranks or the number of females in their har ems. The males sired 7 of the 25 offspring with females outside their own h arems, with higher-ranking males exhibiting greater success monopolizing ac cess to females in their harem than lower-ranking males did. More surprisin gly, the females assigned as the dams of 14 of the 25 offspring could be un equivocally excluded from parentage. The identity of the true dam could be determined for each of these 14 offspring using single-parent PEA and was u ncorrelated with the ranks of these offsprings' sires and whether the offsp ring were born to darns outside the sires' harem groups. The combined effec t of this extraharem mating and kidnapping was that only 12 of the 25 offsp ring were raised within their sires' harem groups. A second group of hamadr yas baboons of identical structure exhibited the same high incidences of in fant kidnapping and mating outside the harem group. It is unclear whether t hese behaviors provide an adaptive advantage or represent aberrant behavior resulting from captivity or other circumstances.