Phaethornis bourcieri

Abstract: Straight-billed Hermit Phaethornis bourcieri inhabits the understory of upland terra-firme forest throughout most of the Amazon basin Currently, two allopatric taxa regarded as subspecies are recognised: P b bourcieri and P b major However, the validity, inter-specific limits, and evolutionary history of these taxa are not yet fully elucidated We use molecular characters to propose a phylogenetic hypothesis for populations and taxa grouped under Phaethornis bourcieri Our results showed that P bourcieri is part of the ‘Ametrornis’ clade, along with P philippii and P koepckeae, and that the subspecies major is more closely related to the latter two species than to populations grouped under nominate bourcieri Our phylogenetic hypotheses recovered three main reciprocally monophyletic clades under nominate bourcieri separated by the lower Negro River and the Branco River or the Branco-Negro interfluve (clades B and C) and the upper Amazon (Solimoes) or lower Maranon / Ucayali rivers (clades C and D) Based on multi-locus phylogeographic and population genetics approaches, we show that P b major is best treated as a separate species, and that P b bourcieri probably includes more than one evolutionary species, whose limits remain uncertain The diversification of the ‘Ametrornis’ clade (P bourcieri, P philippii, and P koepckeae) is centered in the Amazon and appears to be closely linked to the formation of the modern Amazon drainage during the Plio-Pleistocene This article is protected by copyright All rights reserved