50 



Field Marks. Small projection of the middle tail feathers as above and their not 

 being twisted make a field mark of fair reliability in adult birds. 



Nesting. On the ground, on the moors and tundras of the north. 



Distribution. Breeds in the Arctic across the continent and is much more common 

 on the seaboard in migration than inland, where it is a very rare though possibly a regular 

 straggler. 



This is the only Jaeger that is likely to be met with in the interior on 

 the Great Lakes. Other species have been recorded, but upon investigation, 

 except in one instance, they have been found to be young birds incorrectly 

 identified, usually on the ground of their lack of elongated tail. 



38. Long-tailed Jaeger. FR. LE LABBE A LONGUE QUEUE. Stercorarius longi- 

 caudus. L, 21. (Tail 13-25, projection of centre feather beyond outer ones 8.) Very 

 similar in coloration to the preceding, but the long slender middle tail feathers project 7 

 or 8 inches beyond the others instead of only 3. 



Distinctions. The Long-tailed Jaeger although having nearly the measurements 

 of the Pomarine, owing to the great taU length being included, is a much smaller bird 

 than either of the other two species. Size should distinguish it. Juveniles are often con- 

 fused with the Parasitic but the wing characters given under that species are diagnostic. 



Field Marks. It is possible to separate only adult Jaegers in life; the long middle 

 tail feathers being the best guide. 



Nesting. Similar to that of the other Jaegers. 



Distribution. Breeds in the Arctics of Europe, Asia, and America. Is only of rare 

 occurrence on east coast. 



Though the Long-tailed Jaeger has been recorded on the Great Lakes 

 most of such occurrences are wrongly identified juveniles of the preceding 

 species. 



FAMILY LARID.E. GULLS AND TERNS. 



General Description. The Gulls and Terns are Long-winged Swimmers, easily separable 

 from the Jaegers by the shape and construction of the bill which shows a single continuous 

 surface without distinct parts or joints (Figures 4, 5, p. 18). The colours of the adult 

 are usually pure white, with white, pearl-grey, or black mantles, often with black wing- 

 tips, hood, cape, or cheek spots. 



Distinctions. Bill with continuous surface and sharp projecting angle on lower man- 

 dible is sufficient to diagnose the family in all plumages. Colours are quite characteristic, 

 though some species during juvenility are evenly (over all) dark, approaching the dark 

 phases of the Jaegers. 



Field Marks. Coloration and flight characteristics are the best field marks. 



Nesting. Gulls generally build on ground, on rocky ledges or flat shores in sandy, 

 grassy, or marshy places; rarely, in trees. 



Distribution. Gulls and Terns are distributed over all the world, usually near large 

 bodies of water, but sometimes occurring far inland, for instance in our prairie regions. 



Subfamily Larinae. Gulls. 



General Description. With the family description in mind the Gulls can be confused 

 only with the Terns (See p. 55). 



Distinctions. Can be distinguished from the Jaegers by the bill and coloration char- 

 acters. (See family description on previous page) ; from the Terns, by their more robust 

 build and mode of flight. Bills especially are heavier and stronger (compare Figures 4 

 and 5, p. 18). As a rule, tails are square without evident fork. Though as much masters 

 of flight as the Tern they have less agility and perform fewer aerial gymnastics. Young 

 Gulls are often quite brownish and dark in coloration, in marked contrast to the adult. 

 Young Terns are usually light in coloration. 



