How Individual Variation Shapes Ecological Niches in Two <i>Pipistrellus</i> Bat Species

Niche partitioning is a key mechanism explaining species coexistence and biodiversity. While different axes of niche partitioning can account for species coexistence, variation between and within individuals can significantly influence this process. This empirical study investigates niche partitioning in a comprehensive framework using two co-occurring bat species as model organisms: Nathusius’ pipistrelle <i>Pipistrellus nathusii</i> and Kuhl’s pipistrelle <i>P. kuhlii.</i> <i>Pipistrellus kuhlii</i> is a recent invader of the study area, rapidly expanding its geographic range. As human-induced alterations in land cover and climate are likely to accelerate this range expansion, understanding the mechanisms enabling the co-occurrence of these species is crucial. We examined niche partitioning across habitat, time, and resource use, considering variation between species, between-individual, and within-individual levels. Specifically, we analysed the movement patterns of 58 individuals of both species and employed metabarcoding on guano samples to assess resource use. Our results demonstrate that individual variation exceeded species-level differences and varied between species.<i>Pipistrellus nathusii</i> exhibited greater between-individual variation, while the expanding <i>P. kuhlii</i> displayed stronger within-individual variation, which may contribute to its range expansion. Our study suggests an important role of within-individual variation in the ongoing expansion of an invading bat species, reshaping animal communities in the context of global change.<br>Data and scripts of “The ecological niche and individual variation of a rapidly expanding bat”<br><b>a_TriangulationEstimation</b><br>This folder contains the R-scripts required to triangulate the pre-filtered data. First step is to pre-filter data based on the interval between consecutive signals. Then, the bearings are calculated using a cosine approach. Finally, the bearings are triangulated using Azimuthal Telemetry Models (ATM).The fits of the ATM have a size of 56.42 GB. Thus, they are not provided on Dryad, but can be shared on request.<br>Input: Raw dataoutput: Triangulated location estimates including inaccuracy estimates<br><br><b>b_filterRawPoints</b><br>This folder contains the scripts to filter the triangulated locations based on activity (moving vs roosting) and speed.<br>Input: Triangulated location estimates including inaccuracy estimatesOutput: Filtered location estimates<br><br><b>c_MovementModels</b><br>This folder contains the scripts to transform the location data to dynamic Brownian Bridge movement models and burst the data to 30 min, 10 min, and 1 hour intervals.<br>Input: Filtered location estimatesOutput: Movement models, burst to 30 min, 10 min, and 1 hour intervals<br><br><b>d_landscapePreparation</b><br>This folder contains the scripts to crop the land cover data and calculate selection ratios of the respective land cover types.<br>Input: land cover data (Corine, Land Burgenland), movement modelsOutput: Temporal explicit selection ratios<br><b>e_ nicheModels</b><br>This folder contains the scripts to build niche models based on the temporal explicit selection ratios<br>Input: Temporal explicit selection ratiosOutput: Individual niche models<br><b>f_metabarcoding</b><br>This folder contains the analysis of the metabarcoding.<br>Input: Output of metabarcoding analysisOutput: PERMANOVA of metabarcoding results, NMDS and Pianka’s niche overlap<br>生态位分化（niche partitioning）是解释物种共存与生物多样性维持的核心机制。尽管生态位分化的不同维度可阐明物种共存的机制，但个体间与个体内的变异亦会对该过程产生显著影响。本实证研究以两种同域分布的蝙蝠物种作为模式生物，在综合框架下探究生态位分化：分别为纳氏伏翼蝠（*Pipistrellus nathusii*）与库尔氏伏翼蝠（*P. kuhlii*）。库尔氏伏翼蝠（*Pipistrellus kuhlii*）为研究区域的新近入侵物种，其地理分布范围正快速扩张。由于人类活动引发的土地覆盖与气候变化或会加速这一分布扩张，因此阐明这两种物种共存的机制至关重要。本研究从栖息地、时间与资源利用三个维度开展生态位分化分析，同时考量物种间、个体间以及个体内的变异水平。具体而言，我们分析了两个物种共58只个体的活动模式，并通过蝙蝠粪便样本的元条形码测序（metabarcoding）评估其资源利用情况。研究结果显示，个体间变异程度超过了物种间差异，且该变异模式在两个物种间存在差异：纳氏伏翼蝠的个体间变异程度更高，而处于扩张过程中的库尔氏伏翼蝠则表现出更强的个体内变异，这或有助于其分布范围的扩张。本研究表明，个体内变异在入侵蝙蝠物种的持续扩张过程中发挥着重要作用，该发现将在全球变化的背景下重塑动物群落结构。<br>《快速扩张蝙蝠的生态位与个体变异》相关数据与代码脚本<br><b>a_三角定位估算</b><br>本文件夹包含用于对预过滤数据进行三角定位的R脚本。第一步为基于连续信号间的时间间隔对数据进行预过滤；随后采用余弦法计算方位角；最后利用方位遥测模型（Azimuthal Telemetry Models, ATM）对方位角进行三角定位。ATM拟合文件大小达56.42 GB，因此未上传至Dryad数据库，如有需要可按需提供。<br>输入：原始数据<br>输出：包含误差估算的三角定位位置估算结果<br><br><b>b_原始点过滤</b><br>本文件夹包含基于活动状态（移动与栖息）和运动速度对三角定位结果进行过滤的脚本。<br>输入：包含误差估算的三角定位位置估算结果<br>输出：过滤后的位置估算结果<br><br><b>c_运动模型</b><br>本文件夹包含将位置数据转换为动态布朗桥运动模型，并将数据按30分钟、10分钟及1小时间隔进行分段的脚本。<br>输入：过滤后的位置估算结果<br>输出：按30分钟、10分钟及1小时间隔分段的运动模型<br><br><b>d_景观预处理</b><br>本文件夹包含裁剪土地覆盖数据并计算各类土地覆盖类型选择率的脚本。<br>输入：Corine土地覆盖（布尔根兰州）数据、运动模型<br>输出：时空显性选择率<br><br><b>e_生态位模型</b><br>本文件夹包含基于时空显性选择率构建生态位模型的脚本。<br>输入：时空显性选择率<br>输出：个体生态位模型<br><br><b>f_元条形码测序分析</b><br>本文件夹包含元条形码测序分析相关代码。<br>输入：元条形码测序分析输出结果<br>输出：元条形码测序结果的置换多元方差分析（PERMANOVA）结果、非度量多维标度（NMDS）分析结果以及皮安卡生态位重叠指数