Photos of a rare warbler hybrid, Yellow Warbler x Black-throated Blue Warbler (Setophaga petechia x Setophaga caerulescens)

Hybridization can have profound effects on biological diversity; however, predictable inheritance of plumage traits remains poorly understood, especially for rare hybrids that are infrequently documented. We reviewed the literature and compiled a comprehensive list of hybrids from the wood warbler family Parulidae, a diverse radiation of songbirds with divergent plumage traits. We used our compilation to analyze modes of inheritance in wing bar patterns and carotenoid coloration. Finally, we described an unusual hybrid from the University of New Mexico in Albuquerque, New Mexico. We identified evidence of hybridization in 44 of 47 (93%) North American parulid species, with highest rates of hybridization in the genus Setophaga. We found predictable inheritance of plumage patterns between hybrid offspring and parental forms in our two focal traits, which supports the identification of our hybrid as a Yellow Warbler x Black-throated Blue Warbler (S. petechia x S. caerulescens). We based our identification on the extent and pattern of white in the tail, a prominent white wing flag, and our ability to confidently rule out all other alternative parentals. Our results suggest that some hybrid pairings can be confidently identified from phenotype alone, and that phenotypes of rare hybrid warblers likely have some degree of predictability.

杂交作用可对生物多样性产生深远影响，但羽色性状的可预测遗传机制仍有待深入阐释，尤其是针对那些记录稀少的罕见杂交个体。本研究通过文献综述，整理了森莺科（Parulidae）鸟类的杂交类群综合名录。森莺科是一类辐射演化多样的鸣禽类群，其羽毛性状差异显著。基于该名录，本研究分析了翅斑样式与类胡萝卜素着色的遗传模式。最后，我们对采自新墨西哥州阿尔伯克基市新墨西哥大学的一例罕见杂交个体进行了记述。研究显示，47种北美森莺中有44种（占比93%）存在杂交证据，其中林莺属（Setophaga）的杂交发生频率最高。针对选定的两项核心性状，我们发现杂交后代与亲本间的羽毛图案遗传模式具有可预测性，这一结果支持本次杂交个体为北美黄林莺（Yellow Warbler）×黑喉蓝林莺（Black-throated Blue Warbler）的鉴定结论，该杂交组合的学名为S. petechia × S. caerulescens。本次鉴定依据尾羽白色斑块的分布范围与样式、标志性的白色翅斑，并通过严谨排查排除了所有其他可能的亲本组合。本研究结果表明，部分杂交配对可仅通过表型特征实现精准鉴定，且罕见杂交森莺的表型具有一定程度的可预测性。