• Demographic parameters and events in wild moustached tamarins (Saguinus mystax)

      Löttker, Petra; Huck, Maren; Heymann, Eckhard W.; German Primate Centre (2004-12)
      This paper examines demographic events in the context of population structure and genetic relationships in groups of wild moustached tamarins (Saguinus mystax). We used a combination of long-term behavioral observations and genetic data from a total of eight groups from a population in northeastern Peruvian Amazonia. The mean group size was 6.0 (range=4–9), including 2.5 adult males and 1.8 adult females. Within-group relatedness was generally high (r=0.3), and most nonbreeding individuals were either natal or closely related to the respective same-sex breeder. The mean annual persistence of adults in the groups was 70% and 68% for males and females, respectively, and the reproductive tenure of one breeding pair lasted for at least 6 years. Migrations predominantly occurred after stability-disrupting events such as the immigration of new individuals and/or the loss of breeding individuals, or when groups were rather large. Migrations of both breeding and nonbreeding males and females occurred. Our results show that the hypothesis of Ferrari and Lopes Ferrari [Folia Primatologica 52:132–147, 1989] that tamarins live in smaller and less stable groups with lower relatedness compared to marmosets does not generally hold true. In contrast, we found that tamarin groups can consist of predominantly related individuals, and are stable as well. It is also apparent that a single demographic event can produce a chain of subsequent complex demographic changes.
    • Migration

      Huck, Maren; University of Derby; University of Derby; United Kingdom (Wiley, 2017-04)
      Primate societies are not static. Group composition changes due to births and deaths, and also by emigration and immigration of individuals between different groups. These transfers, while considered costly for the individual, have important implications for the individual itself and the population as a whole. While, generally speaking, dispersal is male-biased in strepsirrhine and catarrhine primates and female-biased in platyrrhines, variations even between different populations of the same species become increasingly apparent. This indicates that dispersal is a conditional strategy that depends on numerous external and internal proximate factors, as well as individual cost–benefit calculations. Although the advent of more advanced molecular techniques has started to provide more insights into dispersal patterns, the life of dispersing floaters remains a challenging topic, but is fundamental in order to not only understand the general behavioral ecology and evolution of a species but also help evaluate the viability of populations.