Influence of environmental parameters on movements and habitat utilization of humpback whales ( Megaptera novaeangliae ) in the Madagascar breeding ground

Trudelle, Laurène; Cerchio, Salvatore; Zerbini, Alexandre N.; Geyer, Ygor; Mayer, François-Xavier; Jung, Jean-Luc; Hervé, Maxime R.; Pous, Stephane; Sallée, Jean-Baptiste; Rosenbaum, Howard C.; Adam, Olivier; Charrassin, Jean-Benoit (2016). Influence of environmental parameters on movements and habitat utilization of humpback whales ( Megaptera novaeangliae ) in the Madagascar breeding ground. Royal Society Open Science, 3(12), p. 160616. The Royal Society Publishing 10.1098/rsos.160616

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Assessing the movement patterns and key habitat features of breeding humpback whales is a prerequisite for the conservation management of this philopatric species. To investigate the interactions between humpback whale movements and environmental conditions off Madagascar, we deployed 25 satellite tags in the northeast and southwest coast of Madagascar. For each recorded position, we collated estimates of environmental variables and computed two behavioural metrics: behavioural state of 'transiting' (consistent/directional) versus 'localized' (variable/non-directional), and active swimming speed (i.e. speed relative to the current). On coastal habitats (i.e. bathymetry < 200 m and in adjacent areas), females showed localized behaviour in deep waters (191 ± 20 m) and at large distances (14 ± 0.6 km) from shore, suggesting that their breeding habitat extends beyond the shallowest waters available close to the coastline. Males' active swimming speed decreased in shallow waters, but environmental parameters did not influence their likelihood to exhibit localized movements, which was probably dominated by social factors instead. In oceanic habitats, both males and females showed localized behaviours in shallow waters and favoured high chlorophyll-a concentrations. Active swimming speed accounts for a large proportion of observed movement speed; however, breeding humpback whales probably exploit prevailing ocean currents to maximize displacement. This study provides evidence that coastal areas, generally subject to strong human pressure, remain the core habitat of humpback whales off Madagascar. Our results expand the knowledge of humpback whale habitat use in oceanic habitat and response to variability of environmental factors such as oceanic current and chlorophyll level.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Biotic Interactions
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Hervé, Maxime

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

2054-5703

Publisher:

The Royal Society Publishing

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

05 Apr 2017 15:15

Last Modified:

05 Apr 2017 15:21

Publisher DOI:

10.1098/rsos.160616

PubMed ID:

28083104

Uncontrolled Keywords:

Madagascar, environmental parameters, habitat use, humpback whales, movement patterns, satellite telemetry

BORIS DOI:

10.7892/boris.93232

URI:

https://boris.unibe.ch/id/eprint/93232

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