The systematics of this kite are also confusing. Until relatively recently White-tailed Kites were considered to be the same species as the Black-shouldered Kite, found across much of the Old World. The American Ornithologists' Union, despite many similarities, recognized the two as separate species in 1993. Currently White-tailed Kites in South America are thought to be only racially distinct from larger North American birds. Two other similar kites are found in Australia and are classified as distinct species. Dunk (1995) warns that "until biochemical analyses are conducted on [these] kites, the taxonomy will likely remain in flux."
Erika and I saw but one White-tailed Kite during our March Texas visit. The bird obligingly waited for us to do a U-turn along a south Texas highway, jump out of the car, and take this photograph. Several years ago, we saw a White-tailed Kite in the California's Napa Valley, but never got close enough for a picture.