RT Journal Article
SR Electronic
T1 All alloparents are not equally valuable: Primary breeders and group size explain group reproductive success in cooperatively breeding primates
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 047969
DO 10.1101/047969
A1 Mrinalini Watsa
A1 Gideon Erkenswick
A1 Efstathia Robakis
YR 2016
UL http://biorxiv.org/content/early/2016/04/10/047969.abstract
AB The effect of a cooperatively breeding group’s composition on its reproductive output (GRO) has been difficult to assess across populations and species. Prior research has correlated GRO with age and sex classes, not accounting for uneven sample sizes and pseudoreplication at the group or species level. This study utilizes a multistep modelling approach to assess whether breeding status explains GRO better than age-sex classes among free-ranging saddleback (Saguinus weddelli) and emperor tamarins (S. imperator) in Peru. Dimension reduction analyses were performed on 6 years of morphometric data to assign breeding status to individuals. Three analytical approaches (GLMM, binomial logistic regression and multinomial logistic regression) were used to model the effects of breeding status on GRO in the current dataset and a historical dataset derived from previous studies of wild callitrichids. Though alloparents have long been considered critical to reproductive success in cooperative breeders, these results indicate that group size and the proportion of primary breeders are the most significant factors contributing to GRO. This indicates that reproductive suppression of subordinate females may even be detrimental to GRO and though additional primary breeding males increased GRO, the addition of secondary breeders, male or female, did not.