Dominance relationships and mating success in multimale groups of black and gold howler monkeys (Alouatta caraya) in northern Argentina.

OKLANDER L.I., KOWALEWSKI M.M., ZUNINO G.E.

PRIMATES

Springer Japan

Lugar: Japan; Año: 2008

0032-8332

We studied two multimale groups of black and gold howler monkeys (Alouatta caraya) on Brasilera Island, in the northeast of Argentina, in order to evaluate the existence of dominance hierarchies among males, and to identify correlations between male rank and access to mates. Our results show that linear dominance hierarchies were present in both groups (Landau’s h=1) although reversals in the hierarchies were observed on some seasons. We also noticed that males interacted agonistically with each other more frequently in the group with more females, and that male rank in each season correlated with the number of matings obtained. However, all the adult males in the group mated. It is commonly argued that monopolization of females becomes harder with a higher number of females in the group and when females synchronize their estrous (Nunn 1999). Estrous in A. caraya females is not as conspicuous as in other howler species, and at this study site howlers do not breed seasonally. Studies of many non-seasonally breeding primates species have found a strong relation between male dominance hierarchies and reproductive success (Paul 2004). We suggest that in non-seasonally breeding howlers the number of receptive females is the major factor that prevents male monopolization of females. In our study groups males attempt to obtain and/or maintain higher rank through dyadic interactions in order to obtain greater access to receptive females. However molecular genetic studies are needed to discern if this translates into higher reproductive success.