Diffuse patterns of at-sea movements by tropical seabirds
Abstract: Understanding marine predator distributions is essential if we hope to arrest their catastrophic declines. In temperate and polar seas, predictable oceanographic features create productive hotspots and predator aggregations, which are suitable for designation as protected areas. In the tro...
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| Format: | Article in Journal/Newspaper |
| Language: | unknown |
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Underline Science Inc.
2021
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| Online Access: | https://dx.doi.org/10.48448/mdwn-m927 https://underline.io/lecture/34909-diffuse-patterns-of-at-sea-movements-by-tropical-seabirds |
| Summary: | Abstract: Understanding marine predator distributions is essential if we hope to arrest their catastrophic declines. In temperate and polar seas, predictable oceanographic features create productive hotspots and predator aggregations, which are suitable for designation as protected areas. In the tropics, however, oligotrophic conditions and weaker seasonal cues limit the tendency of marine predators to form lasting concentrations and thereby impede our ability to identify important at-sea areas. Here, we track the non-breeding movements of an assemblage of tropical seabirds (n = 365 individuals, from 10 species and 10 colonies) from across the Western Indian Ocean. These species dispersed widely during non-breeding, covering the entire tropical Indian Ocean, and spent no extended periods of residency in concentrated areas. Habitat selection models revealed divergent species-specific responses to a suite of environmental parameters. This in turn created even species richness with no clear hotspots, either when considering observed tracking data or extended to predicted distributions from colonies across species entire Indian Ocean range. When evaluating the marine protected area network in the region, areas of high species richness were not well captured by MPAs, even if predicted to be fully protected. Dispersive non-breeding movements of tropical seabirds in the Western Indian Ocean are in stark contrast to widespread patterns of biodiversity hotspots at higher latitudes and suggest that at-sea conservation of tropical marine predators requires re-consideration of traditional, spatial methods. This is crucial given the long-term erosion of tropical seabird assemblages but encouraging strides towards the conservation and restoration of colonies on land. Authors: Alice Trevail¹, Malcolm Nicoll², Robin Freeman², Matthieu Le Corre³, Jill Schwarz⁴, Pierre-Andre Adam⁵, Vincent Bretagnolle⁶, Licia Calabrese⁷, Chris Feare⁸, Audrey Jaeger³, Carl Jones⁹, Camille Lebarbenchon³, Ken Norris², Sabine Orlowski³, Patrick Pinet¹⁰, Virginie Plot³, Norman Rattcliffe¹¹, Gerard Rocamora¹², Nirmal Shah¹³, Stephen Votier¹⁴ ¹University of Exeter, ²The Zoological Society of London, ³Université de la Réunion, ⁴University of Plymouth, ⁵Island Conservation Society, ⁶Centre d'Etudes Biologiques de Chize (CEBC-CNRS), ⁷Independent Researcher, ⁸WildWings Bird Management, ⁹Durrell Wildlife Conservation Trust, ¹⁰Parc national de La Réunion, ¹¹British Antarctic Survey, ¹²University of Seychelles, ¹³Nature Seychelles, ¹⁴Heriot-Watt University |
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