Dispersal is a fundamental process in the functioning of animal societies as it regulates the degree to which closely related individuals are spatially concentrated. A species’ dispersal pattern can be complex as it emerges from individuals’ decisions shaped by the cost-benefit tradeoffs associated with either remaining in the natal group or dispersing. Given the potential complexity, combining long-term demographic information with molecular data can provide important insights into dispersal patterns of a species. Based on a 15-year study that integrates multi-year demographic data on six groups with longitudinal and cross-sectional genetic sampling of 20 groups (N=169 individuals, N=21 polymorphic microsatellite loci), we describe the various dispersal strategies of male and female black howler monkeys (Alouatta pigra) inhabiting Palenque National Park, Mexico. Genetically confirmed dispersal events (N=21 of 59 males; N=6 of 65 females), together with spatial autocorrelation analyses revealed that the dispersal pattern of black howlers is bisexual with strong sex-biases in both dispersal rate (males disperse more often than females) and dispersal distance (females disperse farther than males). Observational and genetic data confirm that both males and females can successfully immigrate into established groups, as well as form new groups with other dispersing individuals. Additionally, both males and females may disperse singly, as well as in pairs, and both may also disperse secondarily. Overall, our findings suggest multiple dispersal trajectories for black howler males and females, and longer multi-year studies are needed to unravel which demographic, ecological, and social factors underlie individuals’ decisions about whether to disperse and which dispersal options to take.

Data include genotype data of 181 black howler monkeys residing in 20 social groups inhabiting Palenque National Park, Mexico. Between 2006 and 2020, fecal samples were collected when we could identify the defecator and when samples were uncontaminated by other fecal material. Fresh fecal material (~1 g) was placed in a 7 ml vial with 1.5 ml of RNAlater and subsequently stored at -18 °C until transportation to the Molecular Anthropology Laboratory at New York University for samples collected in 2006–2007 and to the Primate Molecular Ecology and Evolution Laboratory at the University of Texas at Austin for samples collected since 2010. Each individual was genotyped for up to 21 polymorphic microsatellite markers. We repeated homozygous genotype calls at least four times and heterozygous genotype calls at least two times.

The data also include the geographic coordinates (in UTM within the 15 Q zone) of the 18 groups sampled in 2012. These data were used in the spatial autocorrelation analyses. 

See supplementary material associated with the publication for additional information on demography.