A marine lifestyle has enabled the expansion of home range size in mammals

Background/Question/Methods

Among mammals there is a strong positive relationship between body size and the area they use (home range) which is influenced by food availability and the costs associated with an animal’s metabolic needs and locomotion. When re-entering the marine environment, mammals were exposed to a fluid habitat with highly mobile prey, which is likely to drive different home range patterns. Marine mammals attained great size and represent some of the largest mammals on earth, yet they were not included in models that describe our understanding of the relationship between mammalian body size and spatial use. To fill this important gap in our knowledge 312 mammals, including both marine and terrestrial representatives, were used to examine how home range and body size scale.  

Results/Conclusions

Whilst marine mammal home ranges are larger than those of terrestrial mammals of a similar mass, we find that body mass is the principle variable underlying home range size, followed by diet. This suggests that the combined effects of energetic requirements/costs and resource distributions are the main mechanisms driving home range sizes in mammals. We demonstrate that by using an integrative model including phylogenetic information and new data, our knowledge of home range patterns across mammals can be significantly enhanced. With the continued changes in spatial use of mammals caused by human land use and climate change, it is important to further our understanding of the drivers behind mammalian spatial behaviour.