Acoustical investigations of social behaviours of the Northern Resident orca community (Orcinus orca), Canada
Extra CEES Seminar by Melanie Stiffel
NOTE THE DAY!
Melanie Stiffel will present ongoing work Acoustical investigations of social behaviours of the Northern Resident orca community (Orcinus orca), Canada.
Killer whales are very interesting study species since they display a variety of behaviour patterns all over the world but they also show some unique behaviour that only occur in special areas. Up to now the motivation of such a special behaviour was only hunting but not in an orca community in the north of Vancouver Island. At three small beaches in the Robson Bight Ecological Reserve the Northern Resident Orcas practise the Beach Rubbing. With the help of acoustical and visual data this study shows the usage of these beaches and which background this behaviour has. The usage of the Rubbing Beaches could be researched with the help of previous investigations about the orca vocalisation and also the hydrophone at the main beach. Since 2003 the research station Orcalab mounts a camera technique at the Rubbing Beaches that allowed the observation of interactions between the individual orcas and showed exactly the activity in this area. All members of the Northern Residents showed a predominant abundance in the summer months whereas one clan was the most abundant one throughout the year. The acoustical analyses from ten years of data and the 3 years of behaviour data confirm the assumption of a social background of this unique behaviour. Beach Rubbing is an activity of the community that strengthens its togetherness and the beach additionally offers a meeting point which can be a starting point for either social or even sexual interactions for all pods in the given area. Future investigations on different orca communities’ world wide might show similar behaviour patterns with a social background which would underline the findings of this novel long time study on motivation of Beach Rubbing.