We are pleased to announce the publication of our paper in the forthcoming issue of Marine Mammal Science.
Photopoulou T, Fedak MA, Thomas L and Matthiopoulos J. Spatial variation in maximum dive depth in gray seals in relation to foraging. doi 10.1111/mms.12092 Abstract Habitat preference maps are a way of representing animals’ space use in two dimensions. For marine animals, the third dimension is an important aspect of spatial ecology. We used dive data from seven gray seals Halichoerus grypus (a primarily benthic forager) collected with GPS phone tags (Sea Mammal Research Unit) to investigate the distribution of the maximum depth visited in each dive. We modelled maximum dive depth as a function of spatiotemporal covariates using a generalized additive mixed model (GAMM) with individual as a random effect. Bathymetry, horizontal displacement, latitude and longitude, Julian day, sediment type, and light conditions accounted for 37% of the variability in the data. Persistent patterns of autocorrelation in the raw data suggest that individual intrinsic rhythm might be an important factor, not captured by external covariates. The strength of using this statistical method to generate spatial predictions of the distribution of maximum dive depth is its applicability to other plunge and pursuit divers. Despite being predictions of a point estimate, these maps provide some insight into the third dimension of habitat use in marine animals. The capacity to predict this aspect of vertical habitat use may help avoid conflict between animal habitat and coastal or offshore developments. If you would like a reprint, please email theoni.photopou...@uct.ac.za or paste the doi into your browser to download the article. Kind regards, Theoni -- Theoni Photopoulou, Postdoctoral Fellow Department of Statistical Sciences, University of Cape Town Rondebosch 7701, Cape Town, South Africa skype. theoni_p / email. theoni.photopoulou@u <theoni.photopou...@gmail.com> ct.ac.za " Be silly. Be honest. Be kind " Ralph Waldo Emerson
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