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.

解析扩散事件发生的频率、对应生命阶段及空间尺度颇具挑战，尤其针对存在隐秘幼体期且繁殖寿命较长的物种。本研究结合标记重捕（mark–recapture）数据、微卫星遗传数据与种群动态模拟，以濒危、长寿且成熟缓慢的布氏拟龟（Emydoidea blandingii）为研究对象，聚焦筑巢雌性个体，解析其出生扩散与繁殖扩散模式。2010至2013年间，我们在威斯康星州中部的种群中捕获并完成基因分型的布氏拟龟共计310只，其中包含220只筑巢雌性；此外，依托2001至2009年开展的背甲标记（carapace-marking）工作，我们还获取了该种群内3处核心筑巢区域间的移动相关信息。标记重捕分析结果显示，3处核心筑巢区域间的扩散频率极低，年扩散概率不足0.03。被推断存在一级亲缘关系的雌性个体对，更倾向于分布在同一筑巢区域内，而非分处不同区域；且亲缘个体对的占比随筑巢区域间距离的增加而下降。基于种群动态模拟，我们观测到的筑巢雌性亲缘个体对分布特征，与首次繁殖时在邻近筑巢区域间发生出生扩散的概率约为0.1的推论相符。我们基于模拟得到的雌性扩散频率较低的结论，得到了有力佐证：筑巢雌性在小于500米的尺度上存在显著的空间遗传自相关。尽管如此，非筑巢个体（包括雄性与雌性）并未表现出空间遗传自相关，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的移动行为，或是雌性在陆地筑巢区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，可有效厘清出生扩散与繁殖扩散对空间生态学的贡献机制。