Unraveling the dispersal patterns and the social drivers of natal emigration of a cooperative breeding mammal, the golden lion tamarin

Abstract

The study of the social drivers of animal dispersal is key to understanding the evolution of social systems. Among the social drivers of natal emigration, the conspecific attraction, aggressive eviction, and reduced social integration hypotheses predict that sexually mature individuals who receive more aggressive behavior and are engaged in less affiliative interactions are more likely to disperse. Few reports have explored these proximate factors affecting emigration in cooperatively breeding species, particularly of Neotropical primates. In this study, we investigated the dispersal patterns and tested the social drivers of natal emigration in the golden lion tamarin (Leontopithecus rosalia) — an endangered species inhabiting Atlantic rainforests fragments in Brazil. We used behavioral and demographic data collected during 7 years from 68 groups of tamarins inhabiting 20 forest fragments. Our analyses from the 160 dispersing individuals showed that dispersal success is higher for males and for those engaged in parallel dispersal, but that males and females use different strategies to enhance their dispersal success, males immigrate into established groups while females form new groups. We did not find high levels of agonistic behavior among group members before natal emigration. Instead we found that conspecific attraction drives natal emigration in both sexes, while additionally the low level of affiliative interactions within the natal group triggers male emigration. We discuss natal emigration in the broader perspective of the cooperative breeding system and the implications of these findings for the conservation of the species.

Intergroup food transfers in wild golden lion tamarins (Leontopithecus rosalia)

“…Subordinate golden lion tamarins have two main reproductive options: 1) wait for a breeding opportunity in their natal group, while caring for the young of the breeding pair, or 2) emigrate to explore their own breeding opportunities (Romano et al, 2019). Both male and female golden lion tamarins disperse from their natal group, and settle in the first available breeding position or unoccupied area that they encounter, but males tend to disperse more frequently than females, and are more successful when dispersing (Baker & Dietz, 1996;Dietz & Baker, 1993;Moraes et al, 2018;Romano et al, 2019).…”

“…Subordinate golden lion tamarins have two main reproductive options: 1) wait for a breeding opportunity in their natal group, while caring for the young of the breeding pair, or 2) emigrate to explore their own breeding opportunities (Romano et al, 2019). Both male and female golden lion tamarins disperse from their natal group, and settle in the first available breeding position or unoccupied area that they encounter, but males tend to disperse more frequently than females, and are more successful when dispersing (Baker & Dietz, 1996;Dietz & Baker, 1993;Moraes et al, 2018;Romano et al, 2019). Furthermore, males and females use different strategies to emigrate: males are more likely to immigrate into established groups compared to females who are more likely to form new groups (Romano et al, 2019), and females are also more likely to inherit their natal territory than males (Baker & Dietz, 1996).…”

End of the line for the golden lion tamarin? A single road threatens 30 years of conservation efforts

“…This territory requirements render mean local density from 0.05 to 0.10 adults per ha (Hankerson & Dietz, 2014). Both sexes disperse, but female success is based upon finding empty forest areas, whereas male success depends on coalitions to oust resident males (Romano, Martins, & Ruiz-Miranda, 2019). 6-7 years (Holst et al, 2006), and although individuals reach sexual maturity before 2 years, successful reproduction is usually achieved only when they reach 4 years (Dietz, Baker, & Miglioretti, 1994).…”

“…6-7 years (Holst et al, 2006), and although individuals reach sexual maturity before 2 years, successful reproduction is usually achieved only when they reach 4 years (Dietz, Baker, & Miglioretti, 1994). Both sexes disperse, but female success is based upon finding empty forest areas, whereas male success depends on coalitions to oust resident males (Romano, Martins, & Ruiz-Miranda, 2019). The short reproductive life span coupled with a small population size makes this species highly vulnerable to stochastic events (Shaffer & Samson 1985).…”

Spatial Response to Linear Infrastructures by the Endangered Golden Lion Tamarin

“…Social groups consist of a breeding pair and their descendant offspring (different ages). Monogamy is the predominant mating system, but behavioral polygyny and polyandry are also observed [42,43]. Social groups are territorial and their home ranges can vary from 50 to 100 ha depending on vegetation and habitat structure [44,45].…”