Home range sizes correlate positively with resting metabolic rate in bush Karoo rats (Otomys unisulcatus)

Abstract Home range size limits the amount of resources an individual can access; hence, it often increases with energy demands. However, maintaining a large home range also requires more energy expenditure, and foraging over a larger area can decrease search efficiency, especially for central place foragers that travel frequently between a home base and food patches. So far, studies examining the relationship between home range size and individual energy management are limited. We investigated whether resting metabolic rate (RMR) was correlated with home range size in bush Karoo rats ( Otomys unisulcatus ). Using flow-through respirometry and mini-GPS dataloggers, we measured individual RMR and home range size of 25 female adult bush Karoo rats in the wild. No association was found between body mass and home range size, instead, RMR was positively associated with home range size. This indicates a larger home range provides sufficient energy to support increased RMR in female bush Karoo rats, supporting either greater body mass or to fuel energy-costly biological process, which feed back to the ability to utilize alarger home range.