Cloud-forest Pygmy-Owl Glaucidium nubicola Scientific name definitions

The Cloud-forest Pygmy-Owl is so poorly known that it was not even recognized as being distinct from other pygmy-owls (Glaucidium) until it was described as a new species in 1999. It was long confused with the similar and partially sympatric Andean Pygmy-Owl (Glaucidium jardinii) until its vocalizations became known and were studied (1 Robbins, M. B., and F. G. Stiles (1999). A new species of pygmy-owl (Strigidae: Glaucidium) from the Pacific slope of the northern Andes. Auk 116(2):305–315. Close ). In fact, it was Alden H. Miller, from the Museum of Vertebrate Zoology, University of California, who was first to describe—albeit briefly—the song of Cloud-forest Pygmy-Owl under an account of Andean Pygmy-Owl (2 Miller, A. H. (1963) Seasonal activity and ecology of the avifauna of an American equatorial cloud forest. University of California Publications in Zoology 66:1–178. Close ). He already envisaged that the Andean Pygmy-Owls he encountered were actually “something different.”

The species is restricted to very humid cloud forest on the west slope of the Andes, from northern Colombia to southern Ecuador. It replaces Andean Pygmy-Owl at middle elevations on Andean slopes, but their ranges nearly overlap at ca. 2,000–2,200 m above sea level; in turn, Cloud-forest Pygmy-Owl replaces Central American Pygmy-Owl (Glaucidium griseiceps) of lower elevations, whereas Peruvian Pygmy-Owl (Glaucidium peruanum) occurs at both higher and lower elevations in southwest Ecuador, but favors less humid and non-forested habitats.

The song of Cloud-forest Pygmy-Owl comprises a long series of paired whistles, similar in pattern to the allopatric Northern Pygmy-Owl (Glaucidium gnoma) and Costa Rican Pygmy-Owl (Glaucidium costaricanum), to which this species is more closely related than to other Andean taxa. It often vocalizes pre-dawn or at dawn, but some bursts of song can occur throughout the day, especially if overcast; the species also sings on moonlit nights. Like the species’ congeners, it is a fierce predator of both invertebrates and small vertebrates, and nests in tree hollows. At present, it is classified as Vulnerable due to ongoing deforestation across its small geographic range, but little is known about its ecology and population trends.