Vol. II, Pt. I] GIFFORD— BIRDS OF THE GALAPAGOS ISLANDS 3Z 



The forests on Cocos Island are very luxuriant, and the island 

 is well watered, streams flowing down on all sides. It is in this 

 setting that the terns appear to greatest advantage. As a rule, 

 the first intimation a person gets of their presence is a startling 

 clucking over his head. Upon looking up he will find two or 

 three of these beautiful inhabitants of the forest hovering 

 within a yard of his head. After flying about him four or 

 five times, they will dart away among the trees with a flight 

 as sure as that of any woodland bird. 



Over the water their flight was very swift and erratic, and 

 usually at a considerable elevation. None were seen on the 

 water. They paid but little attention to a boat, seldom ap- 

 proaching to examine it. At times they were seen in pursuit 

 of each other, and then their evolutions were the swiftest. 

 One day eight or ten were seen pursuing an Osprey. 



Mr. A. F. Basset Hull, in The Proceedings of the Linnean 

 Society of Nczv South IVales,^ takes exception to the remarks 

 of Messrs. Snodgrass and Heller^ on the method of nesting of 

 this species at Cocos Island. 



A young female (No. 1617 C. A. S.) in juvenal plumage, 

 was obtained at Clipperton. The scapulars, interscapulars, 

 and tertials are strongly washed with russet. The lesser 

 coverts, some of the feathers of the crown and of the sides of 

 the breast, and the two middle rectrices are edged with rus- 

 set terminally. The forehead has a faint tinge of the same 

 color. A few tufts of grayish down still adhere to some of 

 the feathers of the top of the head. The shafts of the pri- 

 maries are olive brown. Three outer rectrices on each side 

 of the tail have pure white shafts, and the remaining rectrices 

 have shafts that are white for the greater part of their length, 

 being olive brown only subterminally. In length of wing and 

 of tarsus this specimen exceeds the average of ten adult females 

 given beyond. It measures in millimeters as follows : Wing 

 250; tail 115; culmen 33.5; tarsus 13; middle toe 21. 



In the Academy's series of twenty adults, dark-shafted 

 rectrices are a marked feature. With a few exceptions, the 

 specimens are in somewhat abraded plumage. No. 1604, 

 male, Oneal Rock, July 27, seems to be in fresh feather ; occa- 

 sional pin-feathers in the crown, back, and rump, are appar- 



'V. 34, p. 662, footnote. 



^Proc. Wash. Acad. Sci., v. 4, p. 511. 



August 8, 1913 



