Anthropogenic natal environmental effects on life histories in a wild bird population

Recent work suggests that the environment experienced in early life can alter life histories in wild populations [1, 2, 3, 4 and 5], but our understanding of the processes involved remains limited [6 and 7]. Since anthropogenic environmental change is currently having a major impact on wild populations [8], this raises the possibility that life histories may be influenced by human activities that alter environmental conditions in early life. Whether this is the case and the processes involved remain unexplored in wild populations. Using 23 years of longitudinal data on the Mauritius kestrel (Falco punctatus), a tropical forest specialist, we found that females born in territories affected by anthropogenic habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults. This shift in life history strategy appears to be adaptive, because fitness was comparable to that of other females experiencing less anthropogenic modification in their natal environment. Our results suggest that human activities can leave a legacy on wild birds through natal environmental effects. Whether these legacies have a detrimental effect on populations will depend on life history responses and the extent to which these reduce individual fitness

Widespread gene flow between oceans in a pelagic seabird species complex

Global-scale gene flow is an important concern in conservation biology as it has the potential to either increase or decrease genetic diversity in species and populations. Although many studies focus on the gene flow between different populations of a single species, the potential for gene flow and introgression between species is understudied, particularly in seabirds. The only well studied example of a mixed-species, hybridising population of petrels exists on Round Island, in the Indian Ocean. Previous research assumed that Round Island represents a point of secondary contact between Atlantic (Pterodroma arminjoniana) and Pacific species (P. neglecta and P. heraldica). This study uses microsatellite genotyping and tracking data to address the possibility of between-species hybridisation occurring outside the Indian Ocean. Dispersal and gene flow spanning three oceans was demonstrated between the species in this complex. Analysis of migration rates estimated using BAYESASS revealed unidirectional movement of petrels from the Atlantic and Pacific into the Indian Ocean. Conversely, STRUCTURE analysis revealed gene-flow between species of the Atlantic and Pacific Oceans, with potential three-way hybrids occurring outside the Indian Ocean. Additionally, geolocation tracking of Round Island petrels revealed two individuals travelling to the Atlantic and Pacific. These results suggest that inter-specific hybrids in Pterodroma petrels are more common than was previously assumed. This study is the first of its kind to investigate gene flow between populations of closely related Procellariform species on a global scale, demonstrating the need for consideration of widespread migration and hybridisation in the conservation of threatened seabirds

Pterodroma microsatellite genotype dataset

Genotypes for Pterodroma petrels generated in GeneMapper from final set of 12 autosomal microsatellite markers. Used in the manuscript for structure and gene flow analysis