Food plants and energetics of the herbivorous lizard, Uromastyx aegyptius microlepis, in Kuwait

摘要

Plant resources of the herbivorous lizard, Uromastyx aegyptius microlepis, were quantified in a sparsely vegetated Rhanterium community in eastern Kuwait. Standing crop biomass increased from 0.5 g/m~2 in the early growth season to a maximum of 2-3 g/m~2 in late March and April. The lizards consumed 15 species of annual and perennial plants. Biomass of the food plants was approximately two-thirds to three-fourths of the total standing crop. The daily energy expenditure of the lizards was estimated by two methods. Calculation based on the standard metabolic rate at 40℃ (Zari 1991) approximates a daily energy expenditure of 11.8 kcal for a 1 kg animal. According to Nagy's relationship (1982) the daily energy cost would be 13.4 kcal. The feeding rate to maintain energy balance would be 3.7 and 4.3 g (dry weight) per day, respectively. Approximate feeding rates of dhubs in the Negev Desert are almost triple this, suggesting that much of the annual energy requirement is acquired and stored during the brief period of plant productivity.