Data from: Linking genetic kinship and demographic analyses to characterize dispersal: methods and application to Blanding’s turtle

Characterizing how frequently, and at what life stages and spatial scales, dispersal occurs can be difficult, especially for species with cryptic juvenile periods and long reproductive life spans. Using a combination of mark–recapture information, microsatellite genetic data, and demographic simulations, we characterize natal and breeding dispersal patterns in the long-lived, slow-maturing, and endangered Blanding’s turtle (Emydoidea blandingii), focusing on nesting females. We captured and genotyped 310 individual Blanding’s turtles (including 220 nesting females) in a central Wisconsin population from 2010 to 2013, with additional information on movements among 3 focal nesting areas within this population available from carapace-marking conducted from 2001 to 2009. Mark–recapture analyses indicated that dispersal among the 3 focal nesting areas was infrequent (<0.03 annual probability). Dyads of females with inferred first-order relationships were more likely to be found within the same nesting area than split between areas, and the proportion of related dyads declined with increasing distance among nesting areas. The observed distribution of related dyads for nesting females was consistent with a probability of natal dispersal at first breeding between nearby nesting areas of approximately 0.1 based on demographic simulations. Our simulation-based estimates of infrequent female dispersal were corroborated by significant spatial genetic autocorrelation among nesting females at scales of <500 m. Nevertheless, a lack of spatial genetic autocorrelation among non-nesting turtles (males and females) suggested extensive local connectivity, possibly mediated by male movements or long-distance movements made by females between terrestrial nesting areas and aquatic habitats. We show here that coupling genetic and demographic information with simulations of individual-based population models can be an effective approach for untangling the contributions of natal and breeding dispersal to spatial ecology.

明确扩散发生的频率、对应生命阶段及空间尺度往往颇具挑战，对于存在隐蔽幼体期且繁殖寿命较长的物种而言尤为如此。本研究结合标记重捕法（mark–recapture）数据、微卫星遗传数据（microsatellite genetic data）与种群统计模拟（demographic simulations），针对寿命长、成熟迟缓且处于濒危状态的布氏拟龟（Blanding’s turtle，学名*Emydoidea blandingii*），以筑巢雌性为核心研究对象，解析其出生扩散与繁殖扩散模式。2010至2013年，我们在威斯康星州中部的一个布氏拟龟种群中，对310只个体（包含220只筑巢雌性）完成了捕获与基因分型工作；此外，通过2001至2009年开展的背甲标记（carapace-marking），我们还获取了该种群内3个核心筑巢区域间的移动信息。标记重捕法分析结果显示，3个核心筑巢区域间的扩散频率极低，年扩散概率不足0.03。经推断具有一级亲缘关系的雌性配对个体，更大概率出现在同一筑巢区域内，而非分散于不同区域；且相关配对个体的占比随筑巢区域间距的增大而降低。基于种群统计模拟，我们观测到的筑巢雌性相关配对个体分布情况，与首次繁殖时在邻近筑巢区域间发生出生扩散的约0.1的概率相符。本研究基于模拟得到的雌性扩散频率较低的结论，得到了空间尺度小于500米的筑巢雌性间显著空间遗传自相关（spatial genetic autocorrelation）结果的验证。不过，非筑巢个体（雄性与雌性）间未检测到空间遗传自相关，这表明种群存在广泛的局部连通性，这种连通性可能由雄性移动介导，或是由雌性在陆地筑巢区域与水生栖息地间开展的长距离移动所介导。本研究证实，将遗传与种群统计信息、基于个体的种群模型模拟相结合，可有效解析出生扩散与繁殖扩散对空间生态学的贡献。