Dear MARMAM members, We thought the following paper might be of interest.
Doniol-Valcroze T., Lesage V., Giard J. & Michaud R. (2012) Challenges in marine mammal habitat modelling: evidence of multiple foraging habitats from the identification of feeding events in blue whales. Endangered Species Research 17: 255-268. Abstract: Effective conservation of animal species depends on accurate identification of their critical habitat. Marine mammals, however, often transit through heterogeneous habitats and perform various activities within short periods of time. The predictive power of habitat modelling techniques can thus suffer from variability in behaviour and the use of multiple habitat types. We used data loggers and ecological-niche factor analysis (ENFA) modelling techniques to determine blue whale Balaenoptera musculus associations with underwater topography on a feeding ground in the St. Lawrence River estuary, Canada. We compared a naïve model that had no knowledge of behaviour with a model that used the locations of feeding events inferred from specific velocity signatures. Blue whales travelled over several habitat types with different characteristics, which confounded modelling efforts when pooled together. The model based on the feeding set had considerably higher predictive power but could not highlight all suitable habitats at the same time. Using cluster analysis, we identified 4 habitat types used for feeding, each corresponding to distinct underwater topographies. Feeding depth and behaviour varied across these habitats, which were used preferentially at different times of the tidal cycle and appeared linked to known prey aggregation mechanisms. Our results suggest that failure to identify feeding activity or to take into account the existence of multiple foraging habitats at a fine scale could result in spurious modelling results. Key words: Habitat modelling · Feeding behaviour · Habitat suitability · ENFA · Blue whale · St. Lawrence River · Marine mammals The paper is part of the ESR special "Beyond Marine Mammal Habitat Modeling: Applications For Ecology And Conservation", and is available in open access at: http://www.int-res.com/abstracts/esr/v17/n3/p255-268/ Questions and comments can be addressed to: thomas.doniol-valcr...@dfo-mpo.gc.ca Best regards, Thomas Doniol-Valcroze Biologist, Marine mammal section Fisheries and Oceans Canada Maurice-Lamontagne Institute 850, route de la mer Mont-Joli, QC, Canada G5H 3Z4 Telephone 418-775-0666 Facsimile 418-775-0740
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