BREEDING PLACES OF SEA BIRDS. 175 



Early the following morning we reached that reef finding, near its 

 exterme northern end, a low fiat sandy island called Usong. It is some 

 400 meters long by 150 wide. The sailing directions state fhat this 

 island has iipon it a rock 20 feet high, as well as some trees, but this 

 is not the case. A boat belonging to some turtle hunters was anchored 

 just off the beach and they had erected on shore a small hut thatched 

 with nipa-palm leaves. Doubtless some timid navigator passing the 

 reef at a distance mistook such a house for a rock. 



There was no vegetation on the island except a few plants of pursley." 

 There can never have been any trees there as the waves evidently dash 

 clear across it during violent storms. 



Brown boobies in enormous numbers were nesting in the sand. 



Near the center of the island there was a large colony of black and 

 white boobies, which we at first mistook for red-legged boobies. Presently, 

 however, the Governor-General called my attention to the fact that they 

 were not red-legged. On the contrary their legs, feet, toes, and nails 

 were of a very dark lead color. Indeed they were almost black. Their 

 bills were dull j^ellow and the bare skin at their bases was of the color 

 of that of the feet and legs. I have since identified these birds as belong- 

 ing to the species Sida cyanops (Sundev.), a species not previously 

 recorded from the Philippines. 



There were numerous noddy terns, Aiiotis stoUdiis (Linnaeus), on 

 the island and they were nesting on the ground among the pursely plants. 

 We did not find any of them nesting on the bare sand. 



There were also a number of large and interesting groups of northern 

 Bergius's terns. The egg hunters had gathered the terns' eggs into 

 heaps preparatory to carrying them off. I compelled these misguided 

 individuals to leave the birds undisturbed throughout the day, and with- 

 in a short time the terns had scattered the heaps of eggs over the sand 

 and were incubating as busily and contentedly as if nothing had 

 happened to disturb them. 



After gathering numerous typical eggs for the collection of the Bureau 

 of Science, shooting a number of fine specimens of the breeding birds, 

 and taking a series of photographs, we sailed to the south skirting 

 the eastern edge of Tlib-bataha Eeef until the small island on Black 

 Eock Eeef hove in sight. Meantime we had passed near a second 

 small sandy island on Tub-bataha Eeef. It seemed to he co\'ered with 

 brown boobies, as was the island on Black Eock Eeef. We landed on 

 the latter, finding numerous nesting brown boobies and northern Ber- 

 gius's terns, but nothing else. 



^ Portulaca oleracea L. 



