Northern pygmy owl

The northern pygmy owl (Glaucidium gnoma), known as northern pygmy-owl in North America, is a small owl native to North and Central America.

Taxonomy

Some experts consider this bird a superspecies with the mountain pygmy owl. The American Ornithologists' Union, the authority for the North American region, does not recognize this split, so the populations are still considered conspecific. Clear differences in the territorial calls by males are the basis for a proposed split, with birds in the high elevations of Arizona and Mexico giving a two-note call while their more northerly congeners give a repeated single-note call. Results from DNA sequence comparisons of cytochrome-b have been weak and inconclusive despite being referenced repeatedly as a justification for taxonomic splitting. Some taxonomists split the northern pygmy owl from the mountain form, in which case the latter takes the nominate form, and the former takes the G. calfornicum specific name.

Subspecies

There are seven recognized subspecies: