Temperature and water deprivation and their effect on ... - Nwrc.gov.sa

GENERAL INTRODUCTIONIn most desert areas, mammals in general <strong>and</strong> thelarge mammals in particular face many deterringproblems. The most important of these are the highambient temperature,scarcity of <strong>water</strong> supply inaddition to the high solar radiation (Grenot, 1992).Most of the Arabian Peninsula is dry <strong>and</strong> arid desert,with great variations in atmospheric temperature(Williamson <strong>and</strong> Delima, 1990). This drastic situationof this part of the world has forced its inhabitantanimals to acclimatize <strong>and</strong> adapt for survival. Theyfaced these difficulties by adopting many ways ofadaptation including morphological, physiological <strong>and</strong>behavioral means.These extremely difficult desertsituations areworse for the large mammals that cannot hide like small mammals in order to avoid the highsolar radiation <strong>and</strong> air temperature, in which casethey have to disperse some of <strong>their</strong> body temperature. ' , . '.. ;- . ' ',' ', . , 0 ,'" -, ':' /> /., • '" I 'to the external surroundings ': (Grenot ·~ 1992). It is anecessity for these animals to be able to cope withthese high ambient temperatures without loss of largequantities of <strong>water</strong> (Williamson et al., 1991).Little is known about the ecophysiology of largemammalsinhabiting arid environments, <strong>and</strong> less isknown about the mammals of the Arabian Peninsula,especially the Arabian gazelles. Previous studies~-'.. ­