Energy expenditure during level locomotion in large desert ungulates: the one‐humped camel and the domestic donkey

Abstract

This study sought to quantify the rate of energy expenditure (), the total cost of transport (COTtot) and the net cost of transport (COTnet) in camels Camelus dromedaries and donkeys Equus asinus during level locomotion. of camels and domestic donkeys were measured at exercise speeds between 0 and 4.17 m s−1. Resting for camels was significantly (P<0.05) lower than predicted, while donkeys exhibited resting values similar to mammals of the same body mass. In both camels and donkeys increased in a nearly linear fashion over the range of exercise speeds. The minimum COTtot of camels in the walking and pacing gaits were not significantly different (P=0.27). Similarly, donkeys exhibited no significant difference (P=0.09) in the minimum COTtot while walking and trotting. In both camels and donkeys, the minimum COTtot was significantly (P<0.05) lower than the predicted COTtot for mammals of the same body mass. The COTnet in both camels and donkeys was determined to be gait dependent and significantly (P<0.05) lower than the predicted minimum COTnet values for walking and running. The low COT seen in camels and donkeys results in energy and water savings.