Systematics

Phaethornis koepckeae is monotypic. Hinkelmann (1988), however, suggested that there was minor geographic variation in wing length, with specimens (of both sexes) from San Martín in northern Peru slightly larger than specimens from elsewhere in the range of the species (see Measurements).

Described as Phaethornis koepckeae Weske and Terborgh 1977; type locality Cerros del Sira, 9º 30'S, 74º 47' W, Huánuco, Peru.

The name koepckeae honors Maria Koepcke, who "devoted nearly 20 years to studying the birdlife of Peru, making many notable contributions" (Weske and Terborgh 1977).

Phaethornis koepckeae was discovered in 1969 in the Cerros del Sira, and was independently discovered only a few years later (1973) by T.A. Parker and colleagues at a site 600 km farther north (Weske and Terborgh 1977).

Phaethornis koepckeae long has been considered to be closely related to Phaethornis philippi (Needle-billed Hermit) (Weske and Terborgh 1977, Hinkelmann and Schuchmann 1997). This relationship has been confirmed by phylogenetic analysis of DNA sequence data, from both mitochondrial and nuclear genes, which identifies koepckeae and philippi as sister species; Phaethornis bourcieri (Straight-billed Hermit) is sister to koepckeae + philippi (McGuire et al. 2014).