Seabirds are crucial indicators of marine ecosystem health, but populations are declining faster than any comparable group of birds, driven primarily by human activities. In the tropical Indian Ocean remaining breeding colonies are frequently restricted to remote oceanic islands. In the western Indian Ocean (WIO) this loss of breeding colonies has led to population fragmentation for many species, with a potential reduction in the movement and exchange of individuals between colonies (i.e., connectivity). Low levels of connectivity can affect a colony’s response to events that may reduce local seabird numbers or its ability to recover following restoration actions, through limiting immigration of new individuals. Therefore, isolated colonies are likely to be less resilient than those that are inter-connected, so to effectively conserve fragmented seabird populations in the WIO establishing the status and drivers of connectivity for species are essential. In seabirds, connectivity is maintained by the dispersal of individuals and our research will assess the degree of connectivity in the WIO for five ecologically contrasting seabird species (greater frigatebird, red-footed booby, sooty tern, tropical and wedge-tailed shearwater) by establishing the rate of transfer of genetic material between colonies (i.e., gene flow). This will identify discrete ‘conservation or management units’ made up of one or more (connected) colonies. In combination with understanding how attractive a colony’s surrounding marine environment is for dispersing seabirds the results of this research will enable us to guide the scale at which seabird conservation policy and actions could be set in the WIO.
Technology can give us the most amazing insights into the natural world and being able to document where seabirds go and how they use the open ocean is not only fascinating, but instrumental in their conservation.
Species Distribution and EcologyBirds Without Borders or Isolated Islands? Connectivity of Western Indian Ocean Seabirds
Species Distribution and EcologyThe Importance of the Chagos Archipelago for Seabirds
Seabirds face threats both on land, principally at their breeding colonies, and at sea. Identifying these threats is key to ensuring the long-term viability of seabird populations but extremely challenging when they spend large periods of their life away from breeding colonies in the open ocean. Across the tropical Indian Ocean my research uses tracking technology to document how a range of seabird species utilise different parts of the Indian Ocean, the threats they might face in these areas and how these then drive changes in their breeding populations. The findings from this research are being used to develop conservation actions both locally, at breeding colonies, and regionally through the identification of priority at-sea areas for protection.