Humpback whale mother-calf interactions : investigating nursing, swimming, and vocal behaviors

• Main Author: Ratsimbazafindranahaka, Maevatiana Nokoloina
• Other Authors: Institut des Neurosciences Paris-Saclay (NeuroPSI), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Université d'Antananarivo, Isabelle Charrier, Olivier Adam, Aristide Andrianarimisa
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2023
• Subjects: Mother-Offspring interactions; Cetaceans; Marine habitat; Biologging; Ontogeny; Interactions mère-Jeune; Cétacés; Habitat marin; Biotélémétrie; Ontogenèse; [SDV.BA]Life Sciences [q-bio]/Animal biology; [SDV.EE]Life Sciences [q-bio]/Ecology; environment; [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences; [SDV.NEU.PC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Psychology and behavior; Humpback Whale; Megaptera novaeangliae; Baleine à bosse
• Online Access: https://theses.hal.science/tel-04316120; https://theses.hal.science/tel-04316120/document; https://theses.hal.science/tel-04316120/file/129239_RATSIMBAZAFINDRANAHAKA_2023_archivage.pdf

Mammals exhibit sophisticated forms of maternal care that are essential for the survival of their young. This thesis aims to better understand mother-calf interactions in aquatic environments by studying humpback whales (Megaptera novaeangliae) mother-calf pairs off Sainte Marie, Madagascar. The method used was based on animal- borne multi-sensor tags. In the first part, a methodology was developed to study suckling behavior, revealing a stereotyped suckling pattern adjusted to the calf's need to breathe at the surface and its growth and occurring in regular sessions throughout the day. The second part explored the swimming behavior of the calves and their mothers, revealing how their activities unwind with age and how the mothers help the calves. The final part examined the vocalizations and their biological functions. Calf calls have been identified as a means of acoustic contact with the mother during vertical separations and are also involved in initiating behaviors such as suckling. This thesis provides crucial information on mother- calf interactions in humpback whales, offering a unique insight into maternal care, calf development, and the use of acoustic signals for communication in a context somewhat different from the terrestrial one. These results have the potential to inform conservation measures and stimulate future research. Les mammifères présentent des formes sophistiquées de soins maternels indispensables à la survie des jeunes. Cette thèse a pour but de mieux comprendre les interactions mère-jeune dans le milieu aquatique en étudiant les couples mère- baleineau de baleine à bosse (Megaptera novaeangliae) dans les eaux côtières de Sainte Marie, Madagascar. La méthode utilisée se base sur l’utilisation de balises multi-capteurs embarquées. Dans la première partie, une méthodologie a été développée pour étudier le comportement d'allaitement, révélant un schéma d'allaitement stéréotypé s’adaptant au besoin du baleineau à aller respirer en surface et à sa croissance, et se faisant sur une base de ...