662 THE BIRDS OF LORD HOWE AND NORFOLK ISLANDS, 



limb of one of the forest trees, preference being given to that 

 great Hibiscus, the White Osik{Lagiinaria Patersoni). This- 

 tree is given to sending out shoots, which die and leave a small 

 hole around which the bark thickens into a ridge an inch or more 

 in height, thus forming an admire^ble resting-place for the Tern's 

 egg. The broad flattish upper surface of the limbs of the other 

 trees, frequently overgrown with lichens or masses of Spanish 

 moss with pendent streamers, also offer reasonably secure accom- 

 modation for the eggs, while less frequently the moss-grown lower 

 branches of the Norfolk Island Pine-tree(^r«?(carm excelsa) are 

 utilised. No material to form a support of any kind for the egg 

 is added to the spot selected for its resting-place.* 



In only three instances did I find an egg at a height of less 

 than twenty feet from the ground, the general height being from 

 thirty to sixty feet. As a rule one pair of birds only inhabits a 

 tree, but from one large oak near the Cable Station two eggs 

 were taken on the same day, and three other birds were sitting 

 close as if on eggs, but in quite inaccessible positions on thin 

 dead branches. The Tern generally selects trees sheltered from 

 the direct force of the prevailing winds from the sea, and the 



* Snodgrass and Heller, in tbeir paper on the Birds of Clipperton and 

 Cocos Islands (Pioc. Wash. Acad. Sc., iv., p. 511, 1902), referring to this- 

 bird, state :— "Abundant in July at Cocos Island, where it was nesting in 

 the tops of tall trees a short distance inland, in company with Micranous 

 diamesus. We did not secure any eggs. The nests, built of twigs, some- 

 what resemble those of a crow. Many nests were frequently found in one 

 tree. The birds were ditficult to obtain from the water, for in flying back 

 and forth from their nests they nearly always remained at the same eleva- 

 tion as the nests." 



I am of opinion that the authors were in error in attributing the nests 

 "built of twigs" to the White Tern; they no doubt belonged to the 

 Micranous. It does not appear possible that the same species would exhibit 

 such different habits in two localities where the conditions were practically 

 identical as regards site, vegetation, and facilities for procuring material 

 for constructing nests were such required. 



