20 BULLETIN 326, U. S. DEPARTMENT OF AGRICULTURE. 



of Playa Sardine in pursuit of a royal tern, calling kik kik kik sharply. The 

 tern zigzagged back and forth, but its pursuer followed without apparent effort, 

 although it finally gave up the chase. August 1 an adult female was seen in 

 San Juan Harbor, circling over the marina and custom-house, curiously watch- 

 ing men at work on the water front. Bowdish (1902-3, p. 359, and in MS.) 

 states that he found an abundant breeding colony on Mona Island. 



On Desecheo Island from June 13 to 16 there were about 175 adults, all hav- 

 ing young three-quarters grown. The majority of the young, one in a nest, 

 were well feathered except about the head, although two were still entirely 

 covered by down. The eggs are said to be laid in October. Four breeding 

 colonies were located on the island, three of them within 400 feet of the 

 water, and one near the top of the highest hill. The young sat quietly on the 

 small platform nests with heads drawn in on the shoulders, but when I came 

 near they clattered their bills loudly, and, snapping and squealing, gave up 

 peace offerings in the form of unsavory masses of partly digested fish, while 

 they crowded back, taking care, however, not to leave the nest. When nests 

 were close together the young were continually fencing with their bills, 

 rattling them loudly, and flapping their wings. One that I kept at camp was 

 always ready to fight, but spent its time when undisturbed in sleeping or 

 resting quietly with head drawn in on the shoulders. The food of the birds 

 was entirely small fish, though the one at camp occasionally swallowed bits 

 of meat. Usually, however, even when placed far down in the throat, meat 

 was ejected by shaking the head violently sidewise. 



Family cares did not seem to weigh heavily upon the adults. In the early 

 morning they were at the nests, but were always on the wing by full daylight, 

 and from then until evening passed most of their time circling in flocks over 

 the island. As nearly as could be ascertained, the young were fed morning 

 and evening and were seldom visited during the rest of the day. Sometimes 

 three flocks of adults were seen circling slowly around, the highest mere specks 

 in the sky. At dusk the birds returned with squealing calls, and there was 

 considerable uproar in the rookeries until all were settled. Usually the long 

 forked tail was held closed in flight, but occasionally was opened and shut 

 scissors fashion. 



These birds may at times be predacious, as shown by the actions of the one 

 which attempted to carry off the tropic bird, and by their habit of pursuing 

 gulls, terns, and possibly boobies, for the food that they may disgorge. The 

 same remarks apply to their economic status as to that of the booby. 



YELLOW-CROWNED NIGHT HERON. Xyctanassa uiolacea (Linnaeus). 

 Yaboa, Yaboa Real, Guanaba. 



The yellow-crowned night heron is apparently becoming rather rare in Porto 

 Rico. Gundlach (1878, p. 363) records it as common, and Bowdish (1902-3. 

 p. 359) also so speaks of it in the localities that he visited. He found it even 

 on Mona Island in August, 1901. It is a bird well known in the coast region, 

 and the fact that it is considered a game bird and prized for the table explains 

 its lessening numbers. The bird inhabits the mangroves and heavy forests cov- 

 ering the swamps, and near Mameyes one was flushed from a coconut palm. 

 In the mangroves they sometimes slip away on foot and hide. 



The single stomach examined was taken in the middle of the day and was 

 entirely empty. Bowdish (loc. cit.), however, found fiddler crabs, two eels, and 

 two crawfish in stomachs which he opened. From these meager data the food 

 of the birds would not seem to differ materially from that of other herons. 

 Detailed examination might show that they feed to some extent on the mole 

 cricket. For the present at least they should be removed from the list of game 

 birds and afforded protection. 



