Phylogeography of the Rufous-tailed Hummingbird (Amazilia tzacatl)

Abstract

Abstract. The Rufous-tailed Hummingbird (Amazilia tzacatl) is a common resident of the neotropical lowlands of Middle America and northern South America. The Escudo Hummingbird (A. t. handleyi), the most distinctive of the five subspecies of A. tzacatl, is endemic to Isla Escudo in Caribbean western Panama. Mitochondrial DNA (mtDNA) sequence variation from across most of the species' range showed five well-defined but shallow clades (maximum uncorrected distance 2.4%) that only partially agreed with subspecific taxonomy. A widespread Middle American clade ranges from southeastern Mexico to central Caribbean Panama and includes birds collected on the Bocas del Toro archipelago. The Escudo Hummingbird fell within this clade and was slightly differentiated (two unique substitutions; uncorrected distance ∼0.2–0.5%). Two additional clades occur in the Pacific regions of southern Middle America. A fourth clade is endemic to eastern Panama (eastern Panama and Darien provinces); a fifth is found in northwestern S...