A preliminary study of habitat and resource partitioning among co-occurring tropical dolphins around Mayotte, southwest Indian Ocean |
| |
| Authors: | Alexandra Gross Jeremy Kiszka Olivier Van Canneyt Pierre Richard Vincent Ridoux |
| |
| Institution: | aLittoral Environnement et Sociétés (LIENSs), UMR6250, Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France;bDirection de l'Environnement et du Développement Durable, Collectivité Départementale de Mayotte, BP 101, 97600 Mamoudzou, Mayotte, France;cCentre de Recherche sur les Mammifères Marins, Université de la Rochelle, 23 Avenue Albert Einstein, F-17071 La Rochelle Cedex, France |
| |
| Abstract: | Mayotte in the southwest Indian Ocean is characterized by high dolphin diversity. They may coexist within a fairly small area around the island because they exploit neither the same preferential habitats nor the same resources. This preliminary study aimed to investigate ecological niche segregation among these delphinid communities: the Indo-Pacific bottlenose dolphin, Tursiops aduncus, the pantropical spotted dolphin, Stenella attenuata, the spinner dolphin, Stenella longirostris, and the melon-headed whale, Peponocephala electra. Two approaches were used. Habitat preferences were investigated by analysing dolphin sighting data and associated physiographical characteristics. Resource partitioning was explored by analysing C and N stable isotopes in skin and blubber biopsies. Only T. aduncus, which showed clear association with coastal habitats in the lagoon, differed from the others in terms of habitat preferences, characterised by shallow depth and slope, and proximity to the coast. All other species shared similar oceanic habitats immediately outside the lagoon, these being of higher depth and slope, greater distance from the coast and were not discernable by discriminant analysis. The two Stenella species and the melon-headed whale displayed very high overlap in habitat physiographic variables. The analysis of stable isotopes confirmed the ecological isolation of T. aduncus and revealed a clear segregation of P. electra compared to the two Stenella that was not apparent in the habitat analysis. This may reflect ecological differences that were not observable from diurnal surface observations. |
| |
| Keywords: | dolphins ecological niche habitats stable isotopes southwest Indian Ocean Mayotte |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
