Gene flow across ocean barriers: investigating genetic connectivity and mechanisms for dispersal in an enigmatic seabird, the red-tailed tropicbird (Phaethon rubricauda)

The red-tailed tropicbird (Phaethon rubricauda, RTTR) is a pelagic seabird that occurs throughout the tropical regions of the Pacific and Indian oceans. In Australia, RTTR are listed as Vulnerable in Queensland under the ‘Nature Conservation Act 1992’ and in NSW under the ‘Biodiversity Conservation Act 2016’, and are considered a high conservation priority. Research on RTTR is largely conducted on island colonies, as their pelagic lives are cryptic and difficult to study, so information on their dispersal patterns is lacking, and colonies on the eastern coast of Australia have received little attention. RTTR exhibit nest-site fidelity, and colonies are often treated as separate populations. However, the formation of a new colony on Lady Elliot Island in the 1980’s suggests that dispersal between islands is occurring, and raises questions about the population genetics of RTTR in Australia.