^'°'i9if ^^] Gross, The YeUoiv-bilkd Tropic-bird. 59 



itself on the wing, but sometimes, especially after being irritated 

 or excited, it may fall to the water before taking flight. When 

 once poised in the air, the Tropic-birds may be classed with the 

 most graceful of sea birds. They have a ^'ery characteristic 

 movement when flying, which is very unlike any other bird I 

 know. Although these birds allow one to approach while on their 

 nests, they are very cautious in returning to the nest if there is any 

 suspicion of the presence of a human being in the immediate vicinity. 



Among the enemies of the Tropic-birds are the colored natives, 

 who molest the nests of the birds in spite of the stringent bird laws 

 of the islands. It is probable the eggs collected are used as food. 

 The robbing of nests for such purposes is said to be common in 

 the West Indies. The wood rat {Mus alexandrinus) , however, 

 is responsible for some of the mysterious disappearances of the 

 many eggs I had under observation. On one of my daily rounds 

 to the nests on Two-Rock Island I caught one of these rats in the 

 act of sucking an egg. The greedy creature was allowed to finish 

 his meal, after which he was killed and preserved as evidence 

 against his kind. I saw no other rats in the act of molesting eggs, 

 but no doubt they find the Tropic-bird eggs a convenient source 

 of food. 



All of the Tropic-birds examined were infested with at least a 

 few and sometimes with thousands of mites, of which there were 

 three species at least. These mites never appear to be fatal to the 

 bird, but nevertheless they must cause a disagreeable irritation 

 when numerous. They feed upon the barbules of the feathers 

 and in some instances this injury to the feathers may be so extensive 

 as to cause a noticeably rough appearance of the plumage. Three 

 species — identified by H. E. Ewing of Cornell University — were 

 found in great abundance on some of the skins. Docophorus 

 hreviantennatus Piaget, belonging to the Mallophaga, is a large 

 black form, which is very conspicuous when seen on a background 

 of pure white feathers. The two species of true mites are Alloptes 

 microphaethon Frb., and Alloptes longipes. n. sp., belonging to the 

 family of Analgesidae. The new species, Alloptes longipes, is 

 described by Dr. Ewing in Psj^che, Vol. 18, No. 1, p 41. 



