2J.2 Whitlock, Birds Breeding in Dampier Archipelago. fi^t^A^ril 



of the female. Fish seemed abundant everywhere, and my boat- 

 man caught a good many crayfish. 



Pandion leucocephalus. White-headed Osprey. — This fine species is 

 the most prominent bird of prey inhabiting Dampier Archipelago. 

 Few islands are without a pair, and some of the larger islands, like 

 Fortescue Island or ShoU Island, possess as many as three occupied 

 eyries. As a general rule the large, massive nests are placed on rocks 

 or on low sand-hills immediatel}- above the high spring-tide line. On 

 some islands a few stunted and very woody bushes grow immediately 

 on the inner side of the sand-hills. It should here be noted that most 

 of the islands are saucer-shaped, and in the hollow interior vegetation 

 is more prolific than on the surrounding sand-hills. Ospreys not 

 infrequently pile their huge nests on the tops of these bushes. In 

 one or two instances I found nests built on the ground in the interior 

 of an island. All were very elaborately constructed of sticks, sea- 

 weed, and sponges. Very often a piece of deal or other soft wood 

 was added. Near Legendre Island I saw an Osprey staggering along 

 with a stick that must have been four feet long, and fairly thick in 

 proportion ; it was just about as much as the bird could manage. 

 The majority of the nests appeared like the work of several seasons, 

 and, being constantly added to, attained a height of three feet or 

 more. The top of the pile, on which the eggs rest, was always flat, 

 and composed of a cushion of brown seaweed and small pieces of 

 sponge, with fragments of coral and shells. The eggs varied from 

 one to three, and in the latter case a considerable time seemed to 

 elapse between the laying of the first and last egg. It might be 

 thought that such richly-marked eggs would be conspicuous in the 

 nest. This is far from the case, the rich chocolate markings on a 

 white background harmonizing very well with the brown seaweed 

 and bits of broken shell or coral usually found in the nests. Generally 

 one of the parent birds watches near the nest, even before the eggs 

 are laid ; but it is never left unguarded once the female has begun to 

 lay. On landing near a nest, one or both parents fly to meet the 

 intruder, uttering querulous whistling notes whilst hovering over- 

 head. If the nest contains eggs both birds fly anxiously about. After 

 a little experience one knows pretty well where to search from 

 watching the flight of the parents. All avian intruders, especially 

 Sea-Eagles, are jealously driven fi^om the neighbourhood of the nest. 

 The female is not a close sitter, and leaves the nest often before it can 

 be detected. On the extensive Barrow Island, which has a coast- 

 line of over 40 miles, Ospreys are not plentiful ; but on the neigh- 

 bouring Double Island, which is simply an island of steep, conical 

 sand-hills with occasional flats clothed with snake-wood and other 

 vegetation, three or four pairs were nesting. Some of these conical 

 sand-hills were clothed with a species of convolvulus, locally called 

 " shore-runner," right up to their summits ; and in several cases 

 Ospreys had wisely chosen these particular sand-hills for nesting-sites. 

 The growth of convolvulus did much towards making the nest incon- 

 spicuous ; one was so well concealed as to be only revealed by 

 observing the sitting bird spring from the nest some distance away. 

 A pair of Ospreys I had under observation on an islet not a quarter 

 of a mile from my camp at Barrow Island behaved in a very erratic 

 manner. I first noticed them continually bringing building material 

 to an old nest in a solitary mangrove. After much labour had been 

 expended they suddenly started to repair an old nest in the sand-hills 



