Blakiston's fish owl  Blakiston's fish owl ("Bubo blakistoni"), the largest living species of owl, is a fish owl, a sub-group of eagle owls which specialize in hunting in riparian areas. This species is a part of the family known as typical owls (Strigidae) which contains most species of owl. Blakiston's fish owl and three related species were previously placed in the genus "Ketupa"; mtDNA cytochrome "b" sequence data is equivocal on which of the two genus names is applied for this species. Its habitat is riparian forest, with large, old trees for nest-sites, near lakes, rivers, springs and shoals that don't freeze in winter. Henry Seebohm named this bird after the English naturalist Thomas Blakiston, who collected the original specimen in Hakodate on Hokkaidō, Japan in 1883. It is more correct to call this species the Blakiston's eagle owl. This is because it is more closely related to the Eurasian eagle-owl by studies of the main subgenus of the species, "B. b. dumeril", than to the subgenus of fish owls that it was believed to be more close to, i.e. "Ketupu". This was proven by osteological (skeleton/bone-related) and DNA-based tests in 2003 by ornithologists/taxonomists Michael Wink and Claus König, author of "Owls of the World". However, the other fish owls are not believed by some authors to be divergent enough to support a separate genus either and thusly some authorities list fish owls as also included in the genus "Bubo". Given that it shares genetic material osteological characteristics with the eagle-owl and also seems to share some characteristics with the other three fish owls (especially the brown species), the place of the Blakiston's fish owls in this evolutionary chain is ambiguous. Some authors have wondered whether the Blakiston's represents an intermediate step between traditional eagle-owls and the other fish owls, despite the current gap in distribution between Blakiston's and other fish owls. Whether other Asian eagle-owls with sideways slanting ear-tufts, namely the spot-bellied ("B. nipalensis"), the barred ("B. sumatranus") and especially the somewhat superficially fish owl-like dusky eagle-owl ("B. coromandus") are closely related to the fish owls and/or the Blakiston's is also unclear.