Mexican Chickadee

The Mexican chickadee (Poecile sclateri) is a small passerine songbird in the family Paridae, the tits and chickadees. It is found in Mexico and the U. S. states of Arizona and New Mexico. == Taxonomy and systematics == The Mexican chickadee was originally described in 1857 as Parus meridionalis by Philip Sclater. However, that species name had already been applied to another species (the marsh tit, now Poecile palustris), by Wilhelm Lilljeborg in 1852, invalidating Sclater's name under the principle of priority. Otto Kleinschmidt noted this, and renamed it Parus sclateri in 1897, honoring the original discoverer. It remained included in the genus Parus for much of the twentieth century. Following a 1996 publication, in 1998 the American Ornithologists' Union reassigned it to Poecile, a genus that had been erected in 1829 and had long been treated as a subgenus of Parus. A 2005 paper used mtDNA cytochrome b sequence data and morphology to agree with that change and suggest it should be universally adopted. BirdLife International's Handbook of the Birds of the World did so in 2016 and the IOC and the Clements taxonomy followed suit by 2018. The Mexican chickadee has four accepted subspecies: P. s. eidos (Peters…