Brown Richard P, Pérez-Mellado V, Diego-Rasilla J, Garcia J A, Naranjo A, Speakman J R
Departamento de Biología Animal, Facultad de Biología, Universidad de Salamanca, 37071, Salamanca, Spain.
Department of Zoology, University of Aberdeen, AB9 2TN, Aberdeen, UK.
Oecologia. 1992 Oct;91(4):500-504. doi: 10.1007/BF00650322.
Population density in the lacertid lizardPodarcis lilfordi on the Mediterranean islet of Nitge, Menorca, Balearic Islands, was found to be 12 190 ind · ha (SE, ±2135), exceeding densities reported for other island or mainland lizard populations. Field metabolic rates inP. lilfordi were measured by the doubly labeled water method, allowing estimation of a population metabolizable energy demand of 13.86 MJ · ha · day-only 9.8% of that for a theoretical mammal population of the same body mass and density. Energy demand was considerably higher than that estimated for other lizard populations, primarily due to high population density but also because of high individual daily energy expenditure (1255 KJ · day; body mass=5.13 g). Field metabolic rates were partitioned into maintenance and activity components by respirometry of captive animals at field body temperatures. Activity metabolism formed the main component (77.4%) of total respiratory metabolism resulting from a combination of long daily activity periods (ca. 12 h), and greatly elevated metabolism during activity (5.7 times greater than resting levels). It is hypothesized that low food availability per individual constrains the time-energy budget of this species, obligating long periods of intense foraging.
在地中海梅诺卡岛的尼特格小岛上，发现丽斑麻蜥（Podarcis lilfordi）的种群密度为12190只/公顷（标准误±2135），超过了其他岛屿或大陆蜥蜴种群报告的密度。采用双标水法测量了丽斑麻蜥的野外代谢率，据此估算出该种群的可代谢能量需求为13.86兆焦/公顷·天，仅为相同体重和密度的理论哺乳动物种群的9.8%。能量需求远高于对其他蜥蜴种群的估计，这主要是由于种群密度高，同时也是因为个体每日能量消耗高（1255千焦/天；体重=5.13克）。通过在野外体温下对圈养动物进行呼吸测量，将野外代谢率分为维持代谢和活动代谢两部分。活动代谢是总呼吸代谢的主要组成部分（77.4%），这是由每日较长的活动时间（约12小时）以及活动期间代谢大幅升高（比休息时水平高5.7倍）共同导致的。据推测，个体可获得的食物量低限制了该物种的时间 - 能量预算，使其不得不长时间进行高强度觅食。
