The Migration of Large Cetaceans: role of pelagic landscapes in the orientation and behaviours of individuals

Several species of large baleen whales migrate through marine landscapes made up of not only images, but also sounds and different perceptions of water quality. They travel thousands of nautical miles between the equator and poles, but these migrations are poorly described. In particular, our present knowledge does not explain how these large mammals orientate themselves in oceans interspersed with obstacles.

The objective of the project C-Scape is to investigate mainly by mathematical modeling how baleen whales perceive the underwater landscapes they cross and how these landscapes structure their behaviour in return.

In this project, we focus on 2 species distributed on all oceans and which perform long migrations, fin whales (Balaenoptera physalus) and humpback whales (Megaptera novaeangliae). Our first working hypothesis is that whales do not have an accurate positioning system (like a GPS) and a mapping system, and hence have a limited perception of their environment, within an order of magnitude of a nautical mile. Our second working hypothesis is that baleen whales can follow a route (in a particular direction and with a given speed), but with variabilities that cumulate along the migration track. According to the information they collect, they can modify their route, or stop to rest or feed.

Our project consists of building first an individual-based model simulating migration at the scale of the entire planet to understand if our hypothesis are consistent with observations performed on the two species of interest. We expect to progress toward a better understanding of whales' migrations, in order to better assess how disturbances of sound landscapes perturb movements of these large mammals, explaining perhaps a part of the disorientations and strandings observed today.

This project is funded by a 2 year grant from INEE (part of the CNRS) as "C-SCAPE : Migration des Grands Cétacés : Rôle des Paysages Pélagiques dans l'Orientation et le Comportement des Individus"

To learn more about our progress on C-Scape, see:

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