Fig. 3

A hybrid network displaying the incidence of hybridization between different members—genera Geothlypis, Mniotilta, Oreothlypis, Setophaga, and Vermivora—of the Parulidae family. Thin, black edges indicate uncommon hybridization, while thick, red edges indicate extensive hybridization (based on Willis et al. 2014). Bird drawings have been used with permission of Handbook of Birds of the World (del Hoyo et al. 2018) and depict species in bold, namely Townsend’s Warbler (S. townsendi), Black-throated Blue Warbler (S. caerulescens), and Golden-winged Warbler (V. chrysoptera)