R-code.

Translocations of freshwater species have become a widespread conservation strategy to mitigate the impacts of habitat fragmentation, yet they are not often rigorously monitored using animal movement data to determine their success. We demonstrate the value of monitoring pre- and post-translocation movements and home-range sizes of a fully-aquatic, benthic stream salamander, the eastern hellbender (Cryptobranchus a. alleganiensis) to determine translocation success. We studied the home range sizes, movements, and habitat use of individuals (n = 27) in two self-sustaining populations (S1 & S2) for one year, and then subsequently collected similar data from a subset of these individuals (n = 17) that were translocated into two nearby streams (T1 & T2) with dam-isolated, declining populations in the Blue Ridge Ecoregion of Tennessee. We collected 1,571 location data points (869 pre-translocation and 715 post-translocation) from four study sites, and evaluated effects of mass, sex, and pre-translocation home range size/sedentariness, as well as habitat covariates on home range size and movements. Hellbender home range sizes increased from pre-translocation estimates at both sites, but response depended primarily on physical characteristics of release sites. Home range and fine-scale movement metrics indicated that hellbenders translocated from S1 to T1 settled in more quickly, had greater site fidelity, and smaller home ranges than hellbenders translocated from S2 to T2. Hellbender movements were influenced by cover rock size and density rather than individual characteristics. Study-long survival rates of translocated hellbenders increased from S1 to T1 (80% to 100%) and decreased from S2 to T2 (76% to 33%). Monitoring pre- and post-translocation movements was a valuable method for evaluating short-term translocation success in a freshwater environment. For future hellbender translocations, managers should prioritize selecting suitable release sites with contiguous boulder-dense areas (1–2 per m2), adequate prey (crayfish) densities (>1/m2), and habitats with low risk of predation.

淡水物种的迁置已成为缓解生境破碎化影响的一项广泛应用的保护策略，但此类行动极少会利用动物运动数据开展严格监测以评估其成效。本研究以一种完全水生的底栖溪流蝾螈——东部大鲵（Cryptobranchus a. alleganiensis）为研究对象，阐明了通过监测迁置前后的运动情况与家域面积来评估迁置成效的价值。我们对两个自我维持种群（S1与S2）中的27只个体开展了为期一年的家域面积、运动模式及生境利用研究；随后，从这些个体中选取17只，将其迁置至田纳西州蓝岭生态区中两处受大坝阻隔、种群呈衰退趋势的邻近溪流（T1与T2），并收集了与之对应的同类数据。我们在四个研究点位共收集到1571个位置数据点（迁置前869个，迁置后715个），并分析了体重、性别、迁置前家域面积/定居性，以及生境协变量对家域面积与运动模式的影响。两处迁置点位的大鲵家域面积均较迁置前有所扩大，但响应程度主要取决于释放点位的物理特征。家域与精细尺度运动指标显示，相较于从S2迁置至T2的个体，从S1迁置至T1的大鲵定居更快、栖地保真度更高，且家域面积更小。大鲵的运动模式主要受遮蔽石块的大小与密度影响，而非个体特征。研究周期内的迁置个体存活率方面，从S1至T1的种群存活率从80%提升至100%，而从S2至T2的种群存活率则从76%下降至33%。监测迁置前后的运动情况，是评估淡水环境中迁置短期成效的有效方法。对于未来东部大鲵的迁置工作，管理者应优先选择具备以下条件的适宜释放点位：连续分布的高密度巨砾区域（每平方米1~2块）、足够的猎物（螯虾）密度（每平方米超过1只），以及低捕食风险的生境。