Linking isotopes and panmixia: high within-colony variation in feather δ2H, δ13C, and δ15N across the range of the American white pelican

Complete panmixia across the entire range of a species is a relatively rare phenomenon; however, this pattern may be found in species that have limited philopatry and frequent dispersal. American white pelicans (Pelecanus erythrorhyncos) provide a unique opportunity to examine the role of long-distance dispersal in facilitating gene flow in a species recently reported as panmictic across its broad breeding range. This species is also undergoing a range expansion, with new colonies arising hundreds of kilometers outside previous range boundaries. In this study, we use a multiple stable isotope (δ2H, δ13C, δ15N) approach to examine feather isotopic structuring at 19 pelican colonies across North America, with the goal of establishing an isotopic basemap that could be used for assigning individuals at newly established breeding sites to source colonies. Within-colony isotopic variation was extremely high, exceeding 100‰ in δ2H within some colonies (with relatively high variation also obser...

物种全分布范围内的完全随机交配（panmixia）是相对罕见的现象；然而，这种模式可能存在于具有有限栖地忠实性（philopatry）和频繁扩散行为的物种中。美洲白鹈鹕（Pelecanus erythrorhyncos）为研究长距离扩散在促进基因流中的作用提供了独特机会——该物种近期被报道在其广阔繁殖范围内呈现随机交配特征。此外，该物种正经历分布范围扩张，新的繁殖群出现在此前分布边界外数百公里处。本研究采用多种稳定同位素（δ²H、δ¹³C、δ¹⁵N）方法，分析北美19个鹈鹕繁殖群的羽毛同位素结构，旨在建立同位素基线图，用于将新繁殖地的个体溯源至其来源繁殖群。繁殖群内同位素变异极高，部分群体中δ²H的变异超过100‰（同时观察到相对较高的变异...