Magpies are passerine birds of the crow family, Corvidae. The names 'jay' and 'magpie' are to a certain extent interchangeable, although this does not accurately reflect the evolutionary relationship between these birds. For example, the Eurasian Magpie seems more closely related to the Eurasian Jay than to the Oriental Blue and Green Magpies, whereas the Blue Jay is not as closely related to either within the Corvid family.
The bird was referred to as a "pie" until the late 16th century when the feminine name "Mag" was added to the beginning. The European Magpie is the only non-mammal known to be able to recognize itself in a mirror.
According to recent analysis, magpies do not form the monophyletic group they are traditionally believed to be — a long tail has certainly evolved (or shortened) independently in multiple lineages of corvid birds. Among the traditional magpies, there appear to be two evolutionary lineages: One consists of Holarctic species with black/white coloration and is probably closely related to crows and Eurasian jays. The other contains several species from South to East Asia with vivid coloration which is predominantly green or blue. The Azure-winged Magpie is a species with a most peculiar distribution and unclear relationships. It may be the single survivor of a long extinct group of corvid genera.
Other recent research has cast doubt on the taxonomy of the Pica magpies, since it appears that P. hudsonia and P. nuttalli may not be different species, whereas the Korean race of P. pica is genetically very distinct from the other Eurasian (and even the North American) forms. Either the North American, Korean, and remaining Eurasian forms are accepted as 3 or 4 separate species, or there exists only a single species, Pica pica.
Holarctic (black-and-white) magpies
Oriental (blue/green) magpies