Navas Carlos A
Department of Ecology and Evolutionary Biology, University of Connecticut, 06269-3042, Storrs, CT, USA.
Oecologia. 1996 Dec;108(4):617-626. doi: 10.1007/BF00329034.
This paper focuses on whether microhabitat selection reduces exposure to cold temperatures in highelevation tropical amphibians. I studied the microhabitat associations and thermal ecology of four anurans (Colostethus subpunctatus, Atelopus sp. nov., Eleutherodactylus bogotensis, and Hyla labialis) that live in the Andes of central Colombia. I compared two populations (3500 m and 2900 m) to evaluate the impact of a change in elevation on microhabitat thermal regimes and frog behavior. Ambient temperatures of frequently used microhabitats (soil surface, retreat sites, bogs, and ponds) were significantly lower at 3500 m. However, for each species the microhabitat associations and general patterns of activity were similar at both elevations. Body temperatures of active frogs were mainly determined by the interaction between microhabitat selection and time of the day, therefore frogs at 3500 m had lower activity temperatures than conspecifics at 2900 m. Terrestrial and diurnal anurans (Atelopus sp. nov.) experienced highly variable activity temperatures. Frogs associated with water bodies (C. subpunctatus, and H. labialis) experienced more moderate and less variable temperatures. Terrestrial, nocturnal frogs (E. bogotensis) exhibited the lowest activity temperatures, and their thermal ecology was strongly affected by increase in altitude. The physical nature of high tropical elevations limits the opportunities for behavioral thermoregulation in amphibians, and increases the importance of physiological adjustments to tolerate a wide thermal range. This may partially explain why only a small number of amphibian species, representing genera that are much more diverse at lower elevations, have been able to exploit these environments.
本文聚焦于微生境选择是否能减少高海拔热带两栖动物暴露于低温环境中的情况。我研究了生活在哥伦比亚中部安第斯山脉的四种无尾目动物（细点丛蛙、新种阿氏蟾蜍、波哥大姬蛙和唇斑雨蛙）的微生境关联和热生态学。我比较了两个种群（海拔3500米和2900米），以评估海拔变化对微生境热状况和蛙类行为的影响。在海拔3500米处，常用微生境（土壤表面、隐蔽场所、沼泽和池塘）的环境温度显著更低。然而，对于每个物种而言，两个海拔高度的微生境关联和一般活动模式相似。活动蛙类的体温主要由微生境选择和一天中的时间之间的相互作用决定，因此海拔3500米处的蛙类比海拔2900米处的同种蛙类活动温度更低。陆生和昼行性无尾目动物（新种阿氏蟾蜍）经历的活动温度变化很大。与水体相关的蛙类（细点丛蛙和唇斑雨蛙）经历的温度更适中且变化较小。陆生夜行性蛙类（波哥大姬蛙）的活动温度最低，其热生态学受到海拔升高的强烈影响。热带高海拔地区的物理性质限制了两栖动物进行行为体温调节的机会，并增加了生理调节以耐受较宽温度范围的重要性。这可能部分解释了为什么只有少数两栖动物物种，代表着在较低海拔地区更为多样的属，能够利用这些环境。
