There is some doubt whether the species of the Philippine Isles is identical with that of Africa.

A difference is noted in the plumage, though very slight.

The disposition of the crest-plumes differs in the two, and the tail-feathers are differently arranged.

In the African species the two middle ones are the longest, while in the serpent-eater of the Philippines it is the two outside feathers that project--giving the bird the appearance of having a "fork" or "swallow" tail.

Some points of distinction have also been observed between the South African bird and that of the Gambia.
The serpent-eater is, however, a very unique bird; and naturalists, failing to class it with either hawks, eagles, vultures, gallinae, or cranes, have elevated it, so as to form a distinct tribe, family, genus, and species, of itself.
In South Africa it frequents the great plains and dry karoos, stalking about in search of its prey.