The water metabolism of a small East African antelope: the dik-dik
Abstract
1. In controlled laboratory experiments, rectal temperature, cutaneous moisture evaporation, and respiratory rate were studied in the dik-dik. The water balance of the dik-dik was investigated when the antelope were either fully hydrated or dehydrated at the environ- mental temperature of 22 0C or at temperatures alternating between 22 0C and 40 0C at 12 h intervals. 2. Faecal, urinary and evaporative water losses were all reduced by varying degrees during dehydration at 22 0C and 22 to 40 'C. The highest urine osmolality recorded was 4318 + 105 mosmol/kg H20 which occurred when the antelopes were severely dehydrated. 3. At the high air temperatures (40 to 45 ?C) cutaneous evaporation measured with a non- ventilated sweat capsule was 19 g H20 rn-2 h-1 and the respiratory rate over 360/min. Thus the respiratory tract seems to be the major avenue for dissipating excess heat in dik-dik exposed to thermal stress. Injection of adrenaline, intravenously, stimulated sweat dis- charges similar to those observed in the small gazelles, and sheep and goats. 4. The low-water exchange and an efficient kidney helps explain the ability of this small antelope to inhabit hot arid areas.
Citation
Proceedings of the Royal Society of London. Series B, Containing papers of a Biological character.1973 Nov 27;184(75):167-78.Publisher
Department of Veterinary Anatomy and Physiology, University of Nairobi
Description
Journal article