Perret Nadège, Pradel Roger, Miaud Claude, Grolet Odile, Joly Pierre
UMR CNRS 5023 Ecology of Fluvial Hydrosystems, Claude Bernard University, F-69622 Villeurbanne Cedex, France.
Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, 1919, route de Mende, F-34293 Montpellier Cedex, France; and.
J Anim Ecol. 2003 Jul;72(4):567-575. doi: 10.1046/j.1365-2656.2003.00726.x.
This work aims to illustrating how it is possible to measure different modalities of adult dispersal in two subdivided populations of the alpine newt (Triturus alpestris). Recent developments in capture-mark-recapture methods make it possible to estimate transience rates from individuals captured only once. In the context of subdivided newt populations, transience is assumed to express nomadic behaviour that contribute to breeding dispersal. Skeletochronology and recaptures within each pond system also made it possible to estimate emigration rates and local dispersal. Two subdivided populations of alpine newts were monitored over 4 and 5 years, respectively. Whereas population A is suspected to have been established for more than 100 years, population B was monitored when colonizing a newly created archipelago of ponds. Transience was detected in each population at similar rates (37% in population A and 35% in the population B). Annual apparent survival rates were estimated as 82% in population A vs. 33% in population B. Similarity of age structures between populations leads us to consider such low survival rates in population B as resulting from emigration. Emigration was thus negligible in population A and was estimated to reach 57·3% in population B. Conversely, high local dispersal (movements within a pond system) was detected in population A, but not in population B. Even though the causation of dispersal in newts (genetic polymorphism vs. phenotypic plasticity) remains unexplored, our study succeeded in identifying several dispersal components that could result from different selective pressures (habitat heterogeneity at different temporal scales). Experimental approaches are needed to investigate the causative bases of these traits.
这项工作旨在说明如何在高山蝾螈（Triturus alpestris）的两个细分种群中测量成年个体扩散的不同方式。标记重捕法的最新进展使得从仅被捕获一次的个体中估计短暂率成为可能。在蝾螈细分种群的背景下，短暂性被认为表达了有助于繁殖扩散的游牧行为。骨骼年代学和每个池塘系统内的重捕也使得估计迁出率和局部扩散成为可能。分别对两个高山蝾螈细分种群进行了4年和5年的监测。种群A被怀疑已经存在了100多年，而种群B是在其殖民一个新创建的池塘群岛时进行监测的。在每个种群中都以相似的速率检测到短暂性（种群A中为37%，种群B中为35%）。估计种群A的年表观存活率为82%，而种群B为33%。种群之间年龄结构的相似性使我们认为种群B如此低的存活率是由迁出导致的。因此，种群A中的迁出可以忽略不计，而种群B中的迁出估计达到57.3%。相反，在种群A中检测到了较高的局部扩散（在一个池塘系统内的移动），而在种群B中未检测到。尽管蝾螈扩散的原因（遗传多态性与表型可塑性）仍未得到探索，但我们的研究成功地识别出了几个可能由不同选择压力（不同时间尺度上的栖息地异质性）导致的扩散组成部分。需要采用实验方法来研究这些特征的成因基础。
