Systematics and evolution Black-billed magpie
in yellowstone bear world (near idaho falls, idaho) externally, black-billed magpie identical european magpie, pica pica, , considered conspecific many sources. american ornithologists union, however, splits separate species, pica hudsonia, on grounds mtdna sequence closer of california s yellow-billed magpie, pica nuttalli, european magpie. if view correct, korean subspecies of european magpie, pica pica sericea, should considered separate species. it appears after ancestral magpie spread on eurasia, korean population became isolated, @ point species crossed bering land bridge , colonized north america, 2 american magpies differentiated. fossil evidence indicates ancestral north american magpie had arrived in current range around mid-pliocene (3–4 mya) , yellow-billed magpie lineage split off rather thereafter due sierra nevada uplift , beginning ice ages. comparatively low genetic difference, however, suggests gene flow between black-billed , yellow-billed magpies still occurred...