I’m tardy to post here that postdoc Dave Toews recently published an ornithologically quite noteworthy paper in the Auk: Ornithological Advances from his PhD work at the University of British Columbia with Darren Irwin. Their study found evidence of strongly heterogeneous genomic divergence between a number of groups in the species complex, which the AOU currently considers a single species. Dave and his co-authors present data that are very likely consistent with the group consisting of at least three distinct species!
All about birds:
https://www.allaboutbirds.org/goodbye-yellow-rump-will-we-see-a-return-to-myrtle-and-audubons-warblers/
Cornell Chronicle:
http://news.cornell.edu/stories/2016/08/butterbutt-warbler-likely-three-different-species-dna-reveals
