Ecological niches of three teuthophageous odontocetes in the northwestern Mediterranean Sea

[摘要] In the northwestern Mediterranean Sea, sperm whales, pilot whales andRisso's dolphins prey exclusively or preferentially on cephalopods. In orderto evaluate their competition, we modelled their habitat suitability withthe Ecological Niche Factor Analysis (ENFA) and compared their ecologicalniches using a discriminant analysis. We used a long term (1995–2005) smallboat data set, with visual and acoustic (sperm whale) detections. Risso'sdolphin had the shallowest and the more spatially restricted principalhabitat, mainly located on the upper part of the continental slope (640 mmean depth). With a wider principal habitat, at 1750 m depth in average, thesperm whale used a deeper part of the slope as well as the closest offshorewaters. Finally, the pilot whale has the most oceanic habitat (2500 m meandepth) mainly located in the central Ligurian Sea and Provençal basin.Therefore, potential competition for food between these species may bereduced by the differentiation of their habitats.

[学科分类] 海洋学与技术