Standard Presentation Australian Marine Sciences Association Annual Meeting 2023

A day in the life of a whale shark: a comprehensive ethogram of the world’s largest fish (#311)

Christine Barry 1 2 , Luciana C Ferreira 1 , Michele Thums 1 , Mark G Meekan 1 , Adrian C Gleiss 2 3
  1. Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, WA, Australia
  2. Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia
  3. Environmental and Conservation Sciences, Murdoch University, Murdoch, WA, Australia

Observational and tagging studies of whale sharks (Rhincodon typus) (n = 24) have reported 16 different behaviours related to feeding (5), locomotion (2), interaction with divers (4), foraging and thermoregulation (4), and navigation (1). These behaviours were used to categorise video from CATS tags that were deployed on 5 whale sharks during May 2017, and 2018, at Ningaloo Reef, WA. Video footage revealed 5 new feeding and locomotion behaviours. All behaviours were collated into an ethogram. The videos showed that feeding occurred 65% of the time throughout the day. Passive ram filter feeding in the water column (mouth open while swimming forward) was the most prevalent behaviour, occurring most frequently during dawn, midday, and afternoon, followed by sub-surface passive feeding (within =< 10 m depth) during morning, and cruising (swimming without RAM filtration) at dusk. The prevalence of feeding behaviours in videos highlight the ecological importance of Ningaloo Reef for whale sharks. The species ethogram we developed can facilitate behavioural comparisons among aggregation sites across the tropics.