Surviving in steep terrain: A lab-to-field assessment of locomotor costs for wild mountain lions (Puma concolor)

Miss Carolyn Dunford¹, Dr Nikki Marks¹, Dr Christopher  Wilmers², Dr Caleb Bryce³, Dr  Barry Nickel², Dr Michael  Scantlebury¹, Dr  Terrie  Williams³

¹School of Biological Sciences, Institute of Global Food Security, Queen’s University of Belfast, Medical Biology Centre, 97 Lisburn Road, BT9 7BL, Belfast, United Kingdom, ²Center for Integrated Spatial Research, Environmental Studies Department, University of California- Santa Cruz, 95060, Santa Cruz, United States of America, ³Department of Ecology and Evolutionary Biology, Coastal Biology Building, 130 McAllister Way, University of California- Santa Cruz, 95060, Santa Cruz, United States of America

In current scenarios of climatic change and habitat loss, many wild animals are moving into novel, energetically challenging environments. Terrain changes associated with these shifts may heighten the travel costs for individuals and could accelerate the decline of populations in new localities. Large carnivores are especially vulnerable to increased transport costs as they travel long distances for unpredictable food resources. We applied a laboratory-to-field approach to examine the impact of terrain steepness on locomotor costs of pumas (Puma concolor). Using open-flow respirometry, oxygen consumption of trained adult pumas was measured during treadmill locomotion on both level and incline surfaces. As expected, incline walking resulted in increased transport costs, which were 1.4 times those of level travel. These data were used to predict daily energy expenditure (DEE) of free-ranging pumas equipped with GPS and accelerometer loggers in the Californian Mountains. Results showed that pumas modified their locomotor behaviour in response to terrain steepness which minimised the energetic impact of incline travel. They achieved this by choosing to walk on shallower paths than the hillside inclines they encountered and by walking more slowly when climbing steeper paths. Thus, pumas seem to be well-adapted to survive in rugged areas. Calculations show that a 20ᵒ increase in terrain steepness would increase the DEE of pumas by less than 1%, because of the applied behavioural modifications. This could prove crucial for individuals encountering new, mountainous environments. Although these results seem encouraging, they only represent one factor influencing a species’ survival in a novel habitat.

Biography:

Carolyn Dunford is a PhD candidate at Queen’s University, Belfast. Her research focuses on how animals’ physiology and behaviour influence their range and habitat at an individual and population level. She specialises in using remote tracking technology to identify and quantify the energetic costs of carnivore behaviour, especially in response to anthropogenic changes in the landscape. Previously, Carolyn completed her BSc (Hons) at the University of Birmingham, UK. She subsequently spent a year conducting carnivore research in South Africa with organisations such as The Cape Leopard Trust and Durham Universities’ Primate and Predator Project, before commencing her PhD.