2l8 SEA-BIRDS 



blue water (never fishing close to land) after flying-fish. In the heat 

 of noon, as in northern gannetries, the downy young lie with their 

 heads hanging over the edge of the nest as if dead; they are fast 

 asleep. Heat is a trial surprisingly well borne by many tropical sea- 

 birds. The small chick of S. dactylatra hatched on the naked rock 

 may be seen climbing on to the webs of the brooding adult in order 

 to avoid the fierce radiation. This species, sometimes called the great 

 white booby, is the largest (and clumsiest on land) of the three, and 

 roosts on open rocks when not breeding. The other two, however, 

 roost much in trees : S. leucogaster will alight on the booms and wooden 

 superstructure of ships and sleep soundly all night. 



The female red-footed booby S. sula, builds a slovenly tree-nest 

 of sticks brought to her by the male (who is smaller in size). The material 

 is laboriously collected from the sea or snapped from the trees, for 

 this booby will not willingly alight on the ground, from which it 

 has difficulty in rising. The young ones show the same fear of the ground 

 and cUng tenaciously to the trees long after they are fully fledged. 

 Deserted by the adults, they climb to the tree-tops, grow thin with 

 much wing flapping and fasting, and at last take off', flying well — 

 far better than the fledgelings of other Sula species, some of which 

 can only flutter downwards to the sea. The red-footed booby is also 

 more crepuscular than the others — it has the largest eye of all the 

 boobies — sleeping much at noon and going out in search of the noc- 

 turnal squid early and late in the day. Some observers suggest that its 

 frequent late return to the roosting ground, after the man-o'-war birds 

 have gone to sleep, is due to fear of these pirates which lie in wait 

 along the edge of the breeding-roosting tree-covered shore. The red- 

 foot's habit of skirting the shore until directly opposite the nesting tree 

 on its return from fishing enables the man-o'-war bird to intercept the 

 food-]aden booby the more certainly. 



The astonishing man-o'-war bird, Fregata magnijicens, obtains a good 

 deal of its food by robbing boobies of theirs. In spite of its wonderful 

 powers of flight it is very restricted in its range from its nesting-sites 

 which, in the North Atlantic, are the West Indies and the Cape Verde 

 Islands. The range is between fifty and seventy miles: the bird's presence 

 in the Pacific was often a guide to "ditched" airmen during the war, as 

 to the nearness of land. Like that of the cormorants, to which it is 

 closely alKed, its plumage becomes water-logged if it is forced to swim: 

 its preen gland is small, the size of a pea, and probably insufficient 

 to yield much oil for waterproofing the feathers. But the man-o'-war 



