on the neighbouring Double Island, and also on the flesh of the small marsupials which abound on Barrow Island. It is somewhat puzzling how the Sea-Eagles catch so many of these nocturnal Petrels. I have reasons for thinking that the latter come out of their burrows to excrete during daylight, and that the Eagles seize the opportunity to prey upon them. I took two eggs from the nest of another pair, which had made their home on the edge of a cliff. Some quarter of a mile away was an untenanted nest built on a rocky point almost isolated from the mainland. This nest was occupied during my visit the previous season, so it would appear that the same nest is not always used in successive seasons. After I had robbed the nest on the cliff before mentioned, however, the parent birds returned to their old home, which they further enlarged and re-lined. It appeared to be ready for eggs just before I left Barrow Island. Other nests on Barrow and the neighbouring islands were built on or near the tops of sand-hills, usually screened on one side by a large snake-wood bush. Two I found by observing the gleaming white head and neck raised up as the sitting bird caught sight of my approach. On a sandy peninsula, the other side of the cove in which my boat was anchored, were the remains of several old Eagles' nests. These had been built on large snake-wood bushes. The nests had no doubt been added to at various times, until the weight of the superincumbent mass, perhaps soddened by a fall of rain, proved too much for the bush, and the whole structure had come crashing to the earth. Despite the numbers of Sea-Eagles on Barrow and the neighbouring islands, immature birds are not much in evidence. I noticed but two, and the wreck of a third one on the beach. Possibly the young are driven away by the parent birds when old enough to forage for themselves.
An Eagle's nest on Passage Island, built on a flat rock, which must have been sprayed by the waves in quite a moderate breeze, contained a young Eaglet and the hinder portion of a large sea-snake, freshly killed.
Haliastur leucosternus. White-headed Sea-Eagle.—This beautiful little Sea-Eagle is not frequently met amongst the islands of the Archipelago, the absence of extensive tracts of mangroves being the reason, no doubt. "Mangrove-Eagle" would be a good name for the species. It is seldom found away from these thickets. Near my camp was a small islet on which a clump of large old mangroves were growing. A pair of White-headed Eagles had their home there. The nest was in the largest bush, and was placed on a thick horizontal limb about 10 feet from the mud below. It was a large and well-made nest of sticks, the cup being deep and well lined with soft seaweeds. The nest contained two heavily-incubated eggs. The female sat very closely, and did not leave her charge until I was climbing up to it. On one occasion I was standing under a nest, only two or three feet above my head, in a mangrove thicket at the north end of the island, when one of the parent birds alighted on the rim of the nest, and on catching sight of me remained gazing at me for several minutes before taking flight again. Another nest, on Double Island, was a very primitive affair, placed in a large snake-wood bush; it contained an infertile egg and a young bird, which menaced me with open beak and extended wings. This nest may have been the work of a Harrier in past seasons, and adapted by the Eagles subsequently.
