Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes
Variation of adult body size of the tortoise Testudo hermanni in Greece: proximate and ultimate causes
复制标题
希腊赫曼陆龟成年体型的变化：直接原因和最终原因
DOI：
10.1111/j.1469-7998.1999.tb01037.x
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
A. Hailey
中科院分区：
文献类型：
--
作者：
R. E. Willemsen;A. Hailey
摘要希腊的 17 个 T. Hermanni 种群的平均成年体型差异很大，长度约为一倍半，质量约为三倍。女性是所有人群中数量最多的性别；两性体型二态性的程度并不随平均体型的变化而变化。种群间体型差异的直接原因是生长持续时间的差异，而不是卵或幼体的大小或幼体的生长速度。 17个种群的成熟年龄（a）随着体型的增大而增加，而贝塔朗菲生长常数（k）则随着体型的增大而减小。 aM 和 M/k（其中 M 是瞬时死亡率）的数量与体型大小无关，这表明种群之间的差异是适应性的，而不是短期干扰的结果。在较冷的地区，体型更大，并且随着纬度和海拔的增加而增大。这种模式与大多数变温动物中发现的模式相反（与伯格曼规则相反），也与陆龟物种之间发生的模式相反。关于体型变化的可能最终原因的几个假设被拒绝，包括适应长期栖息地干扰（土地利用）、性格位移、社会因素、能量学、体温调节、r-K选择、可孵化季节的长度或幼年死亡率的差异。不同地点之间体型差异的最可能的最终原因是成虫死亡率的差异，通过火灾频率与环境温度的相关性。关键词：体型、地理差异、生长、生活史不变量、温度、赫尔曼陆龟
AbstractSeventeen populations of T. hermanni in Greece differed substantially in mean adult body size, over arange of about one and a half times in length and three times in mass. Females were the larger sex in allpopulations; the degree of sexual size dimorphism did not vary with mean body size. The proximate causeof the variation of body size among populations was differences in the duration of growth, rather than eggor hatchling size or the growth rates of juveniles. The age at maturity (a) increased with body size in the 17populations, while the Bertalanffy growth constant (k) decreased with body size. The quantities aM andM/k (where M is the instantaneous mortality rate) were invariant with body size, suggesting that differencesbetween populations were adaptive rather than the result of short-term disturbance. Body size was greaterin cooler areas, and increased with both latitude and altitude. This pattern is opposite to that found inmost ectotherms (the reverse Bergmann’s rule), and to that which occurs between tortoise species. Severalhypotheses about the possible ultimate causes of variation of body size were rejected, including adaptationto long-term habitat disturbance (land use), character displacement, social factors, energetics, thermo-regulation, r-K selection, the length of the season available for incubation, or differences in juvenilemortality. The most likely ultimate cause of size variation between sites is differences in adult mortality,the correlation with environmental temperature being through the frequency of fires.Key words: body size, geographic variation, growth, life history invariants, temperature, Testudo hermanni