Mishana Tyrannulet is a small flycatcher distinguished from its congeners by the combination of drab head, small size, and red bill. It is restricted to poor-soil habitats of northern Peru, where the two disjunct populations might represent separate species. The population that is restricted to white-sands forest (and similar habitats) in the Nanay and Tigre river basins near Iquitos was one of several spectacular discoveries made in the 1990s by José Álvarez Alonso, who performed the first serious ornithological exploration of white-sands forests in Peru. He named the species for P. Avencio Villarejo, an Augustinian missionary who wrote about the people and nature of Peruvian Amazonia (Alvarez Alonso and Whitney 2001). One additional specimen already existed at the time of the discovery: a single individual collected in 1912 at an uncertain location near Moyobamba, Peru. Subsequent fieldwork revealed a separate, disjunct population inhabiting scrubby forests of the Mayo and Huallaga Valleys in San Martín. This undescribed population is vocally distinct from the nominate, and itself might warrant separate species status (Whitney et al. 2013).