Christian Keith A, Corbett L K, Green Brian, Weavers Brian W
School of Biological Sciences, Northern Territory University, 0909, Darwin, Northern Territory, Australia.
Division of Wildlife and Ecology, CSIRO, P.M.B. 44, 0821, Winnellie, Northern Territory, Australia.
Oecologia. 1995 Aug;103(3):349-357. doi: 10.1007/BF00328624.
The field metabolic rates (FMR) and rates of water flux were measured in two species of varanid lizards over five periods of the year in tropical Australia. The energetics of these species were further investigated by directly measuring activity (locomotion) and body temperatures of free-ranging animals by radiotelemetry, and by measuring standard metabolic rate (over a range of body temperatures) and activity metabolism in the laboratory. Seasonal differences in the activity and energetics were found in these goannas despite similar, high daytime temperatures throughout the year in tropical Australia. Periods of inactivity were associated with the dry times of the year, but the onset of this period of inactivity differed with respect to habitat even within the same species. Varanus gouldii, which inhabit woodlands only, were inactive during the dry and late dry seasons. V. panoptes that live in the woodland had a similar seasonal pattern of activity, but V. panoptes living near the floodplain of the South Alligator River had their highest levels of activity during the dry season when they walked long distances to forage at the receding edge of the floodplain. However, during the late dry season, after the floodplain had dried completely, they too became inactive. For V. gouldii, the rates of energy expenditure were 196 kJ kg day for active animals and 66 kJ kg day for inactive animals. The rates of water influx for these groups were respectively 50.7 and 19.5 ml kg day. For V. panoptes, the rates of energy expenditure were 143 kJ kg day for active animals and 56 kJ kg day for inactive animals. The rates of water influx for these two groups were respectively 41.4 and 21.0 ml kg day. We divided the daily energy expenditure into the proportion of energy that lizards used when "in burrows", "out of burrows but inactive", and "in locomotion" for the two species during the different seasons. The time spent in locomotion by V. panoptes during the dry season is extremely high for a reptile (mean of 3.5 h/day spent walking), and these results provide an ecological correlate to the high aerobic capacity found in laboratory measurements of some species of varanids.
在澳大利亚热带地区，对两种巨蜥在一年中的五个时间段进行了野外代谢率（FMR）和水通量率的测量。通过无线电遥测直接测量自由活动动物的活动（运动）和体温，并在实验室测量标准代谢率（在一系列体温范围内）和活动代谢率，进一步研究了这些物种的能量学。尽管澳大利亚热带地区全年白天温度都很高且相似，但在这些巨蜥中发现了活动和能量学的季节性差异。不活动期与一年中的干旱时期相关，但即使在同一物种内，不活动期的开始在栖息地方面也有所不同。仅栖息在林地的古氏巨蜥在干旱和干旱后期不活动。生活在林地的全色巨蜥有类似的季节性活动模式，但生活在南鳄河洪泛区附近的全色巨蜥在干旱季节活动水平最高，此时它们会走很长的距离到洪泛区后退边缘觅食。然而，在干旱后期，洪泛区完全干涸后，它们也变得不活动。对于古氏巨蜥，活跃动物的能量消耗率为196千焦/千克·天，不活动动物为66千焦/千克·天。这些组的水流入率分别为50.7和19.5毫升/千克·天。对于全色巨蜥，活跃动物的能量消耗率为143千焦/千克·天，不活动动物为56千焦/千克·天。这两组的水流入率分别为41.4和21.0毫升/千克·天。我们将每日能量消耗分为两种巨蜥在不同季节“在洞穴中”、“不在洞穴中但不活动”和“在运动中”时所使用能量的比例。全色巨蜥在干旱季节用于运动的时间对于爬行动物来说极高（平均每天行走3.5小时），这些结果为在实验室测量中发现的某些巨蜥物种的高有氧能力提供了生态关联。
