īecause locomotory activities often account for a large proportion of a mammal’s daily energy expenditure (DEE) (see for a discussion of transport costs), energy balance can be compromised in highly mobile carnivores as daily activity increases. One of the most obvious and energetically costly responses necessary to meet the comparatively high-resource demands of a carnivorous lifestyle, is associated with an increase in distance moved in search of food, often requiring travel into and within new habitats. In recent years, the behavioural and physiological repertoire of large predatory mammals to maintain energy balance has been challenged by the magnitude and rapidity of environmental perturbations associated with climate change and habitat loss. The ability of individual animals and animal populations to survive depends, in part, on their ability to balance energy expenditure with energy acquisition within a stochastic environment. While many factors influence survival in novel habitats, we illustrate the importance of behaviours which reduce locomotor costs when traversing new, energetically challenging environments, and demonstrate that these behaviours are utilised by pumas in the wild. They also avoided elevated costs by utilizing slower speeds and shallower path angles. Calculations show that a 20 degree increase in mean steepness of the terrain would increase puma DEE by less than 1% as they only spend a small proportion (10%) of their day travelling. Estimated daily energy expenditure (DEE) based on GPS-derived speeds of free-ranging pumas was 18.3 MJ day − 1 ± 0.2 SEM. Pumas also walked more slowly up steeper paths, thereby minimizing the energetic impact of vertical terrains. Pumas negotiated steep terrain by traversing across hillsides (mean hill incline 17.2° ± 0.3 SEM mean path incline 7.3° ± 0.1 SEM). Incline walking resulted in a 42.0% ± 7.2 SEM increase in the costs of transport compared to level performance. These data were used to predict energetic costs of locomotor behaviours of free-ranging pumas equipped with GPS/accelerometer collars in California’s Santa Cruz Mountains. To examine locomotor costs of a large carnivorous mammal moving in mountainous habitats, the oxygen consumption of captive pumas ( Puma concolor) was measured during treadmill locomotion on level and incline (6.8°) surfaces. Consequently, changes in terrain associated with such moves may heighten energetic costs and effect the decline of populations in new localities. Under current scenarios of climate change and habitat loss, many wild animals, especially large predators, are moving into novel energetically challenging environments.
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