Beyond correlation: integrating environmentally and behaviourally mediated processes in models of marine mammal distributions

Marine species distribution modeling has seen explosive growth in recent years, and the Endangered Species Research Theme Section entitled 'Beyond marine mammal habitat modeling: applications for ecology and conservation' demonstrates that the field of marine mammalogy has been no exception. For the past decade, marine mammal ecologists have been developing habitat models with increasing proficiency and sophistication. However, these efforts have largely focused on correlative analyses of observed species-environment associations, which often have low explanatory power due to the absence of critical, but unaccounted for processes that are important drivers of animal distributions. Here we provide an overview of these processes, advocate for directed studies (e.g. tagging, prey sampling, focal follows, physiological assessment) to address how the processes influence species' distributions, and challenge the modeling community to incorporate these results into their efforts. We also identify a progression of modeling stages from correlative to confirmatory to mechanistic that should lead us to formulate increasingly robust and accurate predictions of species distributions rooted in greater ecological understanding. Given the on-going risks to marine mammals from human activities and climate change, such models are needed for conservation and management now more than ever.