380 NATATORES. 



dusky spots, of a triangular or crescent shape, not unlike 

 those on the under parts of some of the falcons. The 

 young, in their first plumage, are dull brown on the under 

 part, and much more closely mottled, and with smaller spots, 

 than the mature birds. 



This skua is an American species ; but its appearance in 

 this country shows that it is a bird of powerful wing and 

 discursive range. Its habits resemble, to a considerable 

 extent, those of the common skua, only it is not so large 

 and strong, and consequently does not levy its contributions 

 upon such large birds as that species does. Its greater com- 

 parative power of wing enables it to range more to seaward 

 than the other, following the lesser gulls and terns ; and it 

 also passes into lower latitudes, though its breeding places 

 are, generally speaking, in the north. .Altogether, it is a 

 bird of more graceful form than the common skua, though in 

 that respect inferior to the remaining and smaller species. 



RICHARDSON'S SKUA (Lestris Ricliardsonii). 



This species, which is by no means rare as a British bird, 

 especially on the more northerly shores of the country, has 

 been, by most writers on British birds, confounded with, or 

 rather described as, the Arctic skua, a bird with which it 

 has little in common, save the generic characters of the 

 skuas, and the same length, measuring from the beak to the 

 extremity of the produced feathers of the tail. 



Richardson's skua, though not common in the south of 

 England, is by no means rare in North Britain, and it is 

 found as far in the south as Yorkshire. The birds appear on 

 the nesting ground, which is generally in some sort of cover 

 near the sea, but as elevated as possible, in the end of April 

 or in May; and they disperse seaward in August, or, at all 

 events, before the autumnal equinox. The reason of their 

 congregating in the early portion of the season, partly depends 



