Sclater published in the Ibis a classification which was mainly a revision of the system of Huxley, modified by the investigations of Garrod and Forbes and by his own large acquaintance with museum specimens.
They are chiefly noted as the habitat of the gigantic land tortoise (Testudo elephantina), now carefully preserved, and of several rare and peculiar birds, including a rail (Dryolimnas aldabranus), an ibis (Ibis abbottii) and a dove (Alectroenas sganzini).
Among the larger birds are cranes, herons, the ibis, storks, eagles, vultures, falcons, hawks, kites, owls, the secretary birds, pelicans, flamingoes, wild duck and geese, gulls, and of game birds, the paauw, koraan, pheasant, partridge, guinea fowl and quail.
In the garzeros of Venezuela are to be found nearly every kind of heron, crane, stork and ibis, together with an incredible number of Grallatores.
The glossy ibis is occasionally seen.