High fidelity: extra-pair fertilisations in eight Charadrius plover species are not associated with parental relatedness or social mating system

Extra-pair paternity is a common reproductive strategy in many bird species. However, it remains unclear why extra-pair paternity occurs and why it varies among species and populations. Plovers (Charadrius spp.) exhibit considerable variation in reproductive behaviour and ecology, making them excellent models to investigate the evolution of social and genetic mating systems. We investigated inter- and intra-specific patterns of extra-pair parentage and evaluated three major hypotheses explaining extra-pair paternity using a comparative approach based on the microsatellite genotypes of 2049 individuals from 510 plover families sampled from twelve populations that constituted eight species. Extra-pair paternity rates were very low (0 to 4.1% of chicks per population). No evidence was found in support of the sexual conflict or genetic compatibility hypotheses, and there was no seasonal pattern of extra-pair paternity (EPP). The low prevalence of EPP is consistent with a number of alternative hypotheses, including the parental investment hypothesis, which suggests that high contribution to care by males restricts female plovers from engaging in extra-pair copulations. Further studies are needed to critically test the importance of this hypothesis for mate choice in plovers

High fidelity: extra-pair fertilisations in eight Charadrius plover species are not associated with parental relatedness or social mating system

Extra-pair paternity is a common reproductive strategy in many bird species. However, it remains unclear why extra-pair paternity occurs and why it varies among species and populations. Plovers (Charadrius spp.) exhibit considerable variation in reproductive behaviour and ecology, making them excellent models to investigate the evolution of social and genetic mating systems. We investigated inter- and intra-specific patterns of extra-pair parentage and evaluated three major hypotheses explaining extra-pair paternity using a comparative approach based on the microsatellite genotypes of 2049 individuals from 510 plover families sampled from twelve populations that constituted eight species. Extra-pair paternity rates were very low (0 to 4.1% of chicks per population). No evidence was found in support of the sexual conflict or genetic compatibility hypotheses, and there was no seasonal pattern of extra-pair paternity (EPP). The low prevalence of EPP is consistent with a number of alternative hypotheses, including the parental investment hypothesis, which suggests that high contribution to care by males restricts female plovers from engaging in extra-pair copulations. Further studies are needed to critically test the importance of this hypothesis for mate choice in plovers

Population structure and historical demography of South American sea lions provide insights into the catastrophic decline of a marine mammal population

Hoffman J, Kowalski GJ, Klimova A, Eberhart-Phillips L, Staniland IJ, Baylis AMM. Population structure and historical demography of South American sea lions provide insights into the catastrophic decline of a marine mammal population. Royal Society Open Science. 2016;3(7): 160291.Understanding the causes of population decline is crucial for conservation management. We therefore used genetic analysis both to provide baseline data on population structure and to evaluate hypotheses for the catastrophic decline of the South American sea lion (Otaria flavescens) at the Falkland Islands (Malvinas) in the South Atlantic. We genotyped 259 animals from 23 colonies across the Falklands at 281 bp of the mitochondrial hypervariable region and 22 microsatellites. A weak signature of population structure was detected, genetic diversity was moderately high in comparison with other pinniped species, and no evidence was found for the decline being associated with a strong demographic bottleneck. By combining our mitochondrial data with published sequences from Argentina, Brazil, Chile and Peru, we also uncovered strong maternally directed population structure across the geographical range of the species. In particular, very few shared haplotypes were found between the Falklands and South America, and this was reflected in correspondingly low migration rate estimates. These findings do not support the prominent hypothesis that the decline was caused by migration to Argentina, where large-scale commercial harvesting operations claimed over half a million animals. Thus, our study not only provides baseline data for conservation management but also reveals the potential for genetic studies to shed light upon long-standing questions pertaining to the history and fate of natural populations

Chemical fingerprints encode mother-offspring similarity, colony membership, relatedness and genetic quality in fur seals

Stoffel M, Caspers B, Forcada J, et al. Chemical fingerprints encode mother-offspring similarity, colony membership, relatedness and genetic quality in fur seals. Proceedings of the National Academy of Sciences. 2015;112(36):E5005-E5012.Chemical communication underpins virtually all aspects of vertebrate social life, yet remains poorly understood because of its highly complex mechanistic basis. We therefore used chemical fingerprinting of skin swabs and genetic analysis to explore the chemical cues that may underlie mother-offspring recognition in colonially breeding Antarctic fur seals. By sampling mother-offspring pairs from two different colonies, using a variety of statistical approaches and genotyping a large panel of microsatellite loci, we show that colony membership, mother-offspring similarity, heterozygosity, and genetic relatedness are all chemically encoded. Moreover, chemical similarity between mothers and offspring reflects a combination of genetic and environmental influences, the former partly encoded by substances resembling known pheromones. Our findings reveal the diversity of information contained within chemical fingerprints and have implications for understanding mother-offspring communication, kin recognition, and mate choice

Data from: Population structure and historical demography of South American sea lions provide insights into the catastrophic decline of a marine mammal population

Understanding the causes of population decline is crucial for conservation management. We therefore used genetic analysis both to provide baseline data on population structure and to evaluate hypotheses for the catastrophic decline of the South American sea lion (Otaria flavescens) at the Falkland Islands (Malvinas) in the South Atlantic. We genotyped 259 animals from 23 colonies across the Falklands at 281 bp of the mitochondrial hypervariable region and 22 microsatellites. A weak signature of population structure was detected, genetic diversity was moderately high in comparison with other pinniped species, and no evidence was found for the decline being associated with a strong demographic bottleneck. By combining our mitochondrial data with published sequences from Argentina, Brazil, Chile and Peru, we also uncovered strong maternally directed population structure across the geographical range of the species. In particular, very few shared haplotypes were found between the Falklands and South America, and this was reflected in correspondingly low migration rate estimates. These findings do not support the prominent hypothesis that the decline was caused by migration to Argentina, where large-scale commercial harvesting operations claimed over half a million animals. Thus, our study not only provides baseline data for conservation management but also reveals the potential for genetic studies to shed light upon long-standing questions pertaining to the history and fate of natural populations

Physiotherapy after Uncomplicated Calcaneus Fracture

The adult sex ratio (ASR) is a fundamental concept in population biology, sexual selection, and social evolution. However, it remains unclear which demographic processes generate ASR variation and how biases in ASR in turn affect social behaviour. Here, we evaluate the demographic mechanisms shaping ASR and their potential consequences for parental cooperation using detailed survival, fecundity, and behavioural data on 6119 individuals from six wild shorebird populations exhibiting flexible parental strategies. We show that these closely related populations express strikingly different ASRs, despite having similar ecologies and life histories, and that ASR variation is largely driven by sex differences in the apparent survival of juveniles. Furthermore, families in populations with biased ASRs were predominantly tended by a single parent, suggesting that parental cooperation breaks down with unbalanced sex ratios. Taken together, our results indicate that sex biases emerging during early life have profound consequences for social behaviour