BACKGROUND Understanding the demographic processes underlying population dynamics is a central theme in ecology. Populations decline if losses from the population (i.e., mortality and emigration) exceed gains (i.e., recruitment and immigration). Amphibians are thought to exhibit little movement even though local populations often fluctuate dramatically and are likely to go exinct if there is no rescue effect through immigration from nearby populations. Terrestrial salamanders are generally portrayed as amphibians with low migratory activity. Our study uses demographic analysis as a key to unravel whether emigration or mortality is the main cause of "losses" from the population. In particular, we use the analysis to challenge the common belief that terrestrial salamanders show low migratory activity. RESULTS The mark-recapture analysis of adult salamanders showed that monthly survival was high (> 90%) without a seasonal pattern. These estimates, however, translate into rather low rates of local annual survival of only ~40% and suggest that emigration was important. The estimated probability of emigration was 49%. CONCLUSION Our analysis shows that terrestrial salamanders exhibit more migratory activity than commonly thought. This may be due either because the spatial extent of salamander populations is underestimated or because there is a substantial exchange of individuals between populations. Our current results are in line with several other studies that suggest high migratory activity in amphibians. In particular, many amphibian populations may be characterized by high proportions of transients and/or floaters.

中文翻译：

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由于迁徙活动频繁，蝾螈的表观存活率很低。


背景技术了解人口动态背后的人口过程是生态学的中心主题。如果人口损失（即死亡率和移民）超过收益（即招募和移民），人口就会下降。人们认为，尽管当地种群数量经常剧烈波动，但两栖动物几乎没有活动，如果没有附近种群的迁徙带来的救援效果，两栖动物很可能会灭绝。陆生蝾螈通常被描述为迁徙活动较低的两栖动物。我们的研究使用人口分析作为关键，以揭示移民或死亡是否是人口“损失”的主要原因。特别是，我们利用该分析来挑战陆生蝾螈的迁徙活动较低的普遍看法。结果 成年蝾螈的标记-重捕分析表明，月生存率很高（> 90%），没有季节性模式。然而，这些估计意味着当地年生存率相当低，仅为 40% 左右，这表明移民很重要。移民的估计概率为 49%。结论 我们的分析表明，陆生蝾螈表现出比通常认为的更多的迁徙活动。这可能是因为蝾螈种群的空间范围被低估，或者是因为种群之间存在大量的个体交换。我们目前的结果与其他几项研究一致，这些研究表明两栖动物具有高度的迁徙活动。特别是，许多两栖动物种群的特征可能是高比例的瞬态和/或漂浮物。