Marked differences in foraging area use and susceptibility to predation between two closely-related tropical seabirds

Ecological theory predicts that closely-related species must occupy different niches to coexist. How marine top predators achieve this during breeding, when they often gather in large multi-species colonies and are constrained to central-place foraging, has been mostly studied in productive temperate and polar oceans with abundant resources, but less so in poorer, tropical waters. Here, we track the foraging movements of two closely-related sympatric seabirds—the white-tailed and red-tailed tropicbirds Phaethon lepturus and P. rubricauda—breeding on Aldabra Atoll, Seychelles, to investigate potential mechanisms of niche segregation and shed light on their contrasting population trends. Combining data from GPS, immersion, depth and accelerometry loggers, we show that the two species have similar behaviour at sea, but are completely segregated spatially, with red-tailed tropicbirds flying further to feed and using different feeding areas than white-tailed tropicbirds. Using nest-based cam..., The data collection methods are in the paper and its electronic supplementary materials. , , # Data from: Marked differences in foraging area use and susceptibility to predation between two closely-related tropical seabirds [https://doi.org/10.5061/dryad.fttdz0909](https://doi.org/10.5061/dryad.fttdz0909) This dataset is published in the following paper: Fayet AL, Sanchez C, Appoo J, Constance J, Clucas G, Turnbull LA, Bunbury N (2023) Marked differences in foraging area use and susceptibility to predation between two closely-related tropical seabirds. Oecologia. [https://doi.org/10.1007/s00442-023-05459-x](https://doi.org/10.1007/s00442-023-05459-x) There are three datasets: one with the birds' **GPS** **tracking data** and all associated variables such as accelerometer data, immersion data, and environmental data (*GPS\_data.csv*), one on **diving data** from a subsample of birds with depth loggers (*Dive\_data.csv*), and one on **causes of nest failures** (*Predation.csv*). ## Description of the data and file structure All variables in each file are listed below, tho...