Comparative trophic ecology of deep-diving toothed whales

  1. Jesús Alcázar-Treviño 12
  2. Patricia Arranz 12
  3. Jacobo Marrero Pérez 34
  4. Mark Johnson 67
  5. Peter T. Madsen 67
  6. Peter L. Tyack 5
  7. Natacha Aguilar de Soto 12
  1. 1 BIOECOMAC, Departamento de Biología Animal, Edafología y Geología
  2. 2 Universidad de La Laguna.
  3. 3 Asociación Tonina, Investigación y Divulgación del medio natural Marino, San
  4. 4 Cristóbal de La Laguna.
  5. 5 Sea Mammal Research Unit, School of Biology, University of St Andrews
  6. 6 Aarhus Institute of Advanced Studies, Zoophysiology, Dept. of Biology, Aarhus
  7. 7 University.
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Actas:
34th Annual Conference of the European Cetacean Society
  1. Séverine Methion (ed. lit.)
  2. Nathalie Dunel Roig (ed. lit.)
  3. Joyce G. A. Neves (ed. lit.)
  4. Olga Mosca (ed. lit.)
  5. Bruno Díaz López (ed. lit.)

Editorial: European Cetacean Society

Año de publicación: 2023

Páginas: 41

Tipo: Aportación congreso

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Resumen

Deep diving toothed whales evolved to predate on the biggest biomass on Earth in theDeep-Scattering-Layer (DSL) and Benthic-Boundary-Layer (BBL). The behaviouralecology of these more than 20 species of air-breathing predators might includeinterspecific competition leading to spatial segregation or coexistence. Here we usedDTAGs to investigate the vertical foraging niches of 10 Cuvier ́s (Zc) and 16Blainville‟s (Md) beaked whales, and 27 short-finned pilot (Gm) and 4 sperm (Pm)whales. Pm and Zc were tagged in the Ligurian Sea and Md and Gm were tagged off ElHierro and Tenerife. Depth and altitude above the seafloor of the whales while emittingecholocation clicks and buzzes indicate that: i) The four species mainly hunt in themesopelagic realm; ii) Zc is the only species routinely targeting the bathypelagic whileiii) Gm exploits the migration of the DSL to epipelagic waters to feed at night; iv) allprey on benthopelagic resources although Gm does so rarely. We show that all thestudied species have niche overlap, and this is higher during the day than at night. Nicheoverlap and social structure might explain observations of interspecific agonisticbehaviours in species with large body size (Pm) or large group sizes (Gm) that allowthem to defend territories, in contrast with the spatial coexistence of species with smallgroup sizes (Md and Zc) in spite of high niche overlap. The reliance of deep diving apexpredators on resources of the DSL and BBL means that they would be negativelyaffected by emergent human activities such as fishing of the DSL or deep-sea mining.