Interspecific competition and torpor in golden spiny mice: two sides of the energy-acquisition coin.
Interspecific competition and torpor in golden spiny mice: two sides of the energy-acquisition coin.
复制标题
金刺小鼠的种间竞争和麻木：能量获取硬币的两面。
DOI：
--
复制
发表时间：
2011
影响因子：
2.6
通讯作者：
N. Kronfeld
中科院分区：
文献类型：
--
作者：
O. Levy;T. Dayan;N. Kronfeld
我们研究了死海附近炎热的岩石沙漠中金刺鼠的冬眠情况。在这一啮齿类动物群落中，有一种近亲——夜行普通棘鼠，竞争性地将金棘鼠排除在昼夜循环的夜间部分之外，迫使它进入昼间活动；这种时间上的划分使这两个物种能够划分它们的猎物数量，特别是在夏天，当这两个物种的饮食主要由节肢动物组成，并且很大程度上重叠。在4个大型室外围场中，研究了在两种资源水平（天然食物供应和自由添加食物）下普通刺鼠的存在对金刺鼠种群的影响：2个去除普通刺鼠的围场和2个同时添加普通刺鼠种群的围场。我们推测，由于种间竞争和/或资源减少，金棘鼠会增加对冬眠的使用。正如我们所料，补充食物减少了昏睡的总时间。在夏季，当两种不同的活动周期导致猎物种类划分时，去除同族不影响金棘鼠的冬眠。然而，在冬季，昆虫数量较少，两种小鼠在很大程度上重叠为素食，无论是否补充食物，去除普通刺鼠都会减少金刺鼠的冬眠。这一结果表明，冬眠是一种使小型哺乳动物能够维持低资源可用性或高能量需求时期的机制，也可能有助于它们忍受增强的种间竞争时期。这可能是一种重要的短期机制，可以减少竞争，从而提高适应性，特别是对那些获得资源可能有限的从属物种的个体。
We studied the occurrence of torpor in golden spiny mice in a hot rocky desert near the Dead Sea. In this rodent assemblage, a congener, the nocturnal common spiny mouse, competitively excluded the golden spiny mouse from the nocturnal part of the diel cycle and forced it into diurnal activity; this temporal partitioning allows the two species to partition their prey populations, particularly in summer when the diet of the two species is comprised mainly of arthropods, and largely overlap. We studied the effect of the presence of the common spiny mice at two resource levels (natural food availability and food added ad libitum) on populations of golden spiny mice in four large outdoor enclosures: two with common spiny mice removed and two enclosures with populations of both species. We hypothesized that with interspecific competition and/or reduced resources, golden spiny mice will increase their use of torpor. As we expected, supplemented food reduced the total time spent torpid. In summer, when the different activity periods of the two species results in prey species partitioning, removal of the congener did not affect torpor in the golden spiny mouse. However, in winter, when insect populations are low and the two species of mice overlap in a largely vegetarian diet, removal of the common spiny mouse reduced torpor in golden spiny mice, whether food was supplemented or not. This result suggests that torpor, a mechanism that allows small mammals to sustain periods of low availability of resources or high energetic requirements, may also help them to tolerate periods of enhanced interspecific competition. This may be a significant short-term mechanism that reduces competition and hence increases fitness, in particular of individuals of the subordinate species whose accessibility to resources may be limited.