Dear colleagues, On behalf of all the co-authors we are pleased to share two recent publications on kinship and parentage in bottlenose dolphins in Shark Bay, Western Australia:
*********************************** "Small effects of family size on sociality despite strong kin preferences in female bottlenose dolphins" Vivienne Foroughirad, Celine H. Frère, Alexis L. Levengood, Anna M.Kopps, Ewa Krzyszczyk, Janet Mann Abstract: The quantity and quality of individual social relationships is a fundamental feature of social structure for group-living species. In many species, individuals preferentially associate with close relatives, which can amplify social benefits through inclusive fitness. Reproductive variation, dispersal and other factors may nevertheless impact relative kin availability, especially for species with slow life histories. As such, variation in family size can affect the social integration of the individual. Here, we investigated the effects of family size on female sociality in a population of Indo-Pacific bottlenose dolphins, Tursiops aduncus, in Shark Bay, Australia. This population exhibits high fission–fusion dynamics, with females varying widely in gregariousness and both sexes remaining philopatric, providing females with both matrilineal and nonmatrilineal kin as potential associates. We used genetic relatedness data obtained from a large single nucleotide polymorphism (SNP) panel and a spatially explicit null model to measure females' propensities to form affiliations with both related and unrelated individuals. We found that females had strong social preferences for matrilineal close (first, second and third degree) kin, but also significant preferences for nonmatrilineal close and more distant kin compared to unrelated individuals. Despite these preferences, we found only small effects of kin availability on individual social position. Stronger and more consistent effects were attributable to individual foraging ecology, although much of the variation remains unexplained. Overall, our models suggest that while female dolphins have strong kin preferences, their social connectivity is not determined by family size; rather, individual foraging strategies and high fission–fusion dynamics enable a diverse repertoire of social strategies to coexist within a population. Link to article: https://authors.elsevier.com/a/1g9rkmjL~dpv *********************************** "Reproductive timing as an explanation for skewed parentage assignment ratio in a bisexually philopatric population" Vivienne Foroughirad, Molly H.F. McEntee, Anna M. Kopps, Alexis L. Levengood, Celine H. Frère, Janet Mann Abstract In mammals, reproductive success can often be directly observed for females, but not males. Early-life correlates of female reproductive success can also be easier to observe due to higher rates of philopatry. Though relatively uncommon, populations in which both sexes remain in their natal home ranges can facilitate studies of mate choice and sex-specific drivers of reproductive success. Genetic parentage assessment in these systems should be more complete due to spatial philopatry since the pool of potential mothers and fathers should be equally accessible for sampling. Nevertheless, many studies still report more maternities than paternities even when individuals are randomly sampled with respect to age and sex. This discrepancy is often attributed to unobserved outbreeding. Here, we investigate two potential drivers for biased genetic parentage assignment in a bisexually philopatric community of bottlenose dolphins in which twice as many maternities as paternities are assigned to randomly sampled adults. We examine whether this pattern can best be explained by (1) sex differences in reproductive timing or (2) high levels of extra-community mating. We use long-term data on female calving success to search for biases in our genetic data collection and to constrain simulations of male reproductive timing patterns that could generate our observed data. We find that the majority of the skew in parentage assignment could be explained by differences in reproductive timing, with a smaller putative role of extra-community mating. We discuss how explicitly considering age effects as well as outbreeding can improve our understanding of sex-specific drivers of reproductive success. Link to article: https://link.springer.com/article/10.1007/s00265-022-03233-2 Please contact infommdolp...@gmail.com if you would like a PDF of either article
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