ORDER OF LONG-WINGED SWIMMERS 



Order Longipennes 



jIRDS of the order of Long-winged Swimmers are cosmopolitan in distribution 

 and are generally seen on the wing over or near water. In the order are three 

 families : Skuas and Jaegers, Gulls and Terns, and Skimmers. They resemble 

 most nearly the Tube-nosed Swimmers of all the water birds, but the character 

 of the nostrils plainly distinguishes them without reference to internal anatomy. 

 These birds have the nostrils lateral and open. The wings are long and pointed. 

 Usually the tail is long. The legs are comparatively free and project from 

 near the center of the body ; the thighs are bare for a short distance ; the tarsi 

 are covered with horny shields of varying sizes. The toes are four in number, 

 but the hind one, which is elevated, is very small (sometimes rudimentary) ; 



the front toes are webbed. Their bills are strong and thick ; the Skuas, Jaegers, and Gulls 



have hooked, hawklike bills ; the Terns have sharply pointed ones ; and those of the Skimmers 



are bladelike. 



Although there is no sexual variation in coloration in the species included in this order, 



there are seasonal and age differences. Their voices are shrill or harsh. Fish is the main 



item of their diet. 



The eggs are few, usually numbering but three. The young are covered with down 



when hatched, but are helpless and the parents care for them in and out of the nest for 



some time. 



SKUAS AND JAEGERS 



Order Lougipciuics: family Stcrcorariida: 



'HE Skuas and Jaegers are closely related to the Gulls and Terns; in fact they 

 are Gulls with habits and structure modified sufficiently to justify their inclusion 

 in a distinct family, the Stercorariidcc, while still remaining in the same order, 

 the Long-winged vSwimmers. Not the least striking of these modifications is 

 a well-developed thieving propensity, with the result that they are often and 

 variously called " Robber Gulls," "Sea Hawks," "Teasers," and "Boat- 

 swains." Generally they are aggressive and daring birds, graceful, skillful 

 and powerful in flight, b}' reason of which they are able to overtake their weaker 

 and more timid relatives and force them to disgorge their food, which the pur- 

 suer catches in its fall. Because of these practices they are often spoken of 

 as parasites, but the practice itself is essentially predatory rather than parasitic. 



The birds' bad habits are not confined to this aerial robbery, however, for certain species 

 are known actually to eat young birds and eggs, and even small mammals. 



The Skuas and Jaegers have wings of only moderate length for this group, the primaries 

 are unusually wide and are rounded at the ends. The tail is relatively very short, but is 

 broad and nearly even, the middle pair of feathers being larger than the others in adults. 

 The body is stocky and heavy and powerfully muscled. The claws are strong, sharp, and 

 curved. 



There is general tendency toward a sooty blackish coloration of the upper parts in the 

 older birds with a gilding of the head and hindneck and a whitening of the shafts of the 

 white feathers toward their bases. The young are smaller than the adults and are- profusely 

 streaked with rufous; several years are required to reach the color and dimensions of the 

 adults. 



