380 



INTRODUCTION TO ZOOLOGY. 



284) annually take possession of an island about thirty acres 

 in extent, and build their nests.* In Ireland, the Black-headed 

 Gulls frequent, for the same purpose, the gravelly beach of a 

 portion of Ram's Island in Lough Neagh; and so closely are 

 the nests placed over the ground, that Mr. W. Thompson 



Fig. 284. BLACK-HEADED GULL. 



informs us, that he and some friends, when visiting the place, 

 had to use great circumspection in putting down their feet, 

 that they might not do injury to the nests or eggs. This 

 species, as stated by the gentleman just mentioned, is that 

 which is most abundant in Belfast Bay, and not the one 

 to which the name of " Common Gull" (L. Canus) is applied. 

 Their evolutions are extremely varied and beautiful, exhibiting 

 both power of wing and grace of movement. 



Of the Petrels, the best known species is that which is the 

 smallest of British web-footed birds, the Stormy Petrel 

 (Thalassidroma pelagica). They crowd round vessels before 

 and during stormy weather, partly for the sake it is supposed of 

 shelter, and partly for that of food. Sailors regard them with 

 superstitious feelings, and have long given them the name of 

 "Mother Carey's Chickens/ ' from some hag of the olden time, 

 whose name would have passed into oblivion had it not been 



* Bishop of Norwich's Familiar History of Birds, vol. ii. p. 246. 



