Do the new-born calves of humpback whales (Megaptera novaeangliae) have a preference to position themselves at the side of their mother?

  • Anjara T. Saloma Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France Zoology and Animal Biodiversity, University of Antananarivo, 101 Antananarivo, Madagascar Cetamada association, Barachois Sainte Marie Island (515), Madagascar
  • Schédir Marchesseau Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Moncada, España Cetamada association, Barachois Sainte Marie Island (515), Madagascar
  • Isabelle Charrier Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France
  • Aristide Andrianarimisa Zoology and Animal Biodiversity, University of Antananarivo, 101 Antananarivo, Madagascar
  • Emmanuel Antogiorgi Duocean, Port de Saint Gilles, Rue Général de Gaulle, 97434, Ile de La Réunion
  • Olivier Adam Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France Institut d'Alembert, équipe Lutheries Acoustique Musicale (LAM), CNRS UMR 7190, Université UPMC, Paris, France
Keywords: humpback whale, calf, laterality, behaviour, preferred position

Abstract

Spatial proximity to mothers is a key factor in offspring survival in group-living mammals. In humpback whales (Megaptera novaeangliae), an extreme migrating species, new-born calves stay close to their mothers. This proximity can be modified by the presence of other congeners or other species. The spatial relationship between mother and calf can therefore vary with social contexts. The position of the calf relative to its mother was investigated in different social contexts: alone, with one or several escorts; and in the presence of free divers. The positions of the calves in the 3D space surrounding their mothers were recorded using video footage of mother-calf pairs in 3 breeding sites located in the Indian and Pacific oceans, with the space methodically divided into ten positions. Calves mainly preferred positions above their mother, either on the right or the left; a strategy allowing the calf to be in an optimal position to breathe and to benefit from the hydrodynamic aspiration flow of its mother. A position below the mother was significantly related to resting behaviour, involving physical contacts with the mother and thus reinforcing their social bond. Finally, calves in the presence of free divers neither approached nor moved away from them, suggesting limited direct impact on their behaviour. 

Author Biographies

Anjara T. Saloma, Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France Zoology and Animal Biodiversity, University of Antananarivo, 101 Antananarivo, Madagascar Cetamada association, Barachois Sainte Marie Island (515), Madagascar
I am interested in mother-offspring interactions in the humpback whale, Megaptera novaeangliae. 
Acoustic signals and other sensory cues such as visual and physical contact ensure biological functions essential to the survival of individuals. If acoustic communication in humpback whale is widely studied for males’ songs, there is a huge gap regarding the social sounds, especially the vocalizations between mother and calf. An exhaustive study investigating the vocal repertoire of the mother and her calf in relationship with the social context and the audience (presence of other conspecifics) is essential to fill this gap of knowledge on social interactions of large marine mammals. An experimental approach was used to test the biological functions of these signals, and to define the strategies of communication. 
Schédir Marchesseau, Facultad de Veterinaria, Universidad CEU Cardenal Herrera, Moncada, España Cetamada association, Barachois Sainte Marie Island (515), Madagascar
I am interested in animal behaviour. After obtaining my master degree in human and animal ethology, I started working on the humpback whale research project in Madagascar coastal area.  Currently a veterinary student, I am mostly focused on anatomy, pathologic anatomy, physiology, social behaviour, neuroethology and bioacoustics.
Isabelle Charrier, Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France
I am interested in animal communication in mammals, especially in pinnipeds. I investigate the coding-decoding processes of individual recognition between mother and offspring, and how individual recognition systems vary in regards to ecological and environmental constraints. Pinnipeds are an excellent model to study vocal communication since they show different social structure (from solitary to highly colonial species) and different reproductive systems (from serial monogamous to highly polygynous species). Involvement of other sensorial modalities in individual recognition mechanisms such as vision and olfactory are also investigated.
Aristide Andrianarimisa, Zoology and Animal Biodiversity, University of Antananarivo, 101 Antananarivo, Madagascar
Experienced Science Coordinator with a demonstrated history of working in the non-profit organization management industry. Strong education professional skilled in Sustainable Development, Corporate Social Responsibility, Conservation Biology, Sustainability, and Statistical Data Analysis.
Emmanuel Antogiorgi, Duocean, Port de Saint Gilles, Rue Général de Gaulle, 97434, Ile de La Réunion
As a whale/ dolphin watching promotor, I am involved in scientific research on humpback whales and dolphins by providing data to the researchers.
Olivier Adam, Institute of Neurosciences Paris Saclay, France, NeuroPSI-CNRS, bat. 446, University Paris Sud Orsay, 91400 Orsay, France Institut d'Alembert, équipe Lutheries Acoustique Musicale (LAM), CNRS UMR 7190, Université UPMC, Paris, France
My main focus are signal processing and pattern recognition applied to Bioacoustic applications. I'm working on detection and localization of marine mammals using passive acoustics. My research project consists to analyse the sound emitted by cetaceans, especially sperm whales, blue whales and recently humpback whales. These studies are based on the segmentation of recordings and on the extraction of the pertinent information for characterizing the species or the individuals.
Published
2018-07-27
Section
Articles

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eISSN: 0856-860X
print ISSN: 0856-860X