The White-headed Osprey, though not an abundant species, is generally diffused over every portion of Australia suited to its habits; I myself shot it in Recherche Bay, at the extreme south of Van Diemen’s Land; and Mr. Gilbert found it breeding both at Swan River on the western, and at Port Essington on the northern shores of Australia. Like its near allies of Europe and America, of which it is a beautiful representative in the southern hemisphere, it takes up its abode on the borders of rivers, lakes, inlets of the sea, and the small islands lying off the coast. Its food consists entirely of living fish, which it procures precisely after the manner of the other members of the genus, by plunging down upon its victim from a considerable height in the air with so true an aim as rarely to miss its object, although an immersion to a great depth is sometimes necessary to effect its accomplishment. Its prey when secured is borne off to its usual resting-place and devoured at leisure. Wilson’s elegant description of the habits and manners of the American bird is in fact equally descriptive of those of the present species. Independently of its white head, this species differs from its near allies in the much lighter colouring of the tarsi, which are yellowish white slightly tinged with grey. The nest being of great size is a very conspicuous object; it is composed of sticks varying from the size of a finger to that of the wrist, and lined with the softer kinds of sea-weed. It is usually placed on the summit of a rock, but is sometimes constructed on the top of a large _Eucalyptus_; always in the vicinity of water. A nest observed by Mr. Gilbert in Rottnest Island measured fifteen feet in circumference. The eggs are two in number, of a yellowish white, boldly spotted and blotched with deep rich reddish brown, which colour in some specimens is so dark as to be nearly black; other specimens again are clouded with large blotches of purple, which appear as if beneath the surface of the shell. The medium length of the eggs is two inches and five lines, and the breadth one inch and nine lines. When near the water its flight is heavy and flapping, but when soaring aloft at a great altitude its actions are the most easy and graceful imaginable, at one moment appearing motionless, and at another performing a series of beautiful curves and circles, apparently for mere enjoyment; for from the great height at which they are executed it is hardly to be conceived that the bird can be watching the motions of its finny prey in the waters beneath.