LIFE HISTOKIES OF NORTH AMERICAN GULLS AND TERNS. 49 



Egg dates. — Pribilof Islands : Thirteen records, June 10 to July 7 ; 

 seven records, June 25 to July 3. Northern Bering Sea: Nine rec- 

 ords, June 10 to July 20 ; five records, June 20 to July 0. 



RISSA BREVIR0STR13 (Bruch). 



BED-LEGGED KIITIWAKE. 



HABITS. 



This is one of the species which I expected to find breeding 

 abundantly among the Aleutian Islands, but I was disappointed to 

 find that it was far from common about any of the islands that were 

 visited. As we passed Akutan Island on the way to Unalaska I saw 

 a large number of idttiwakes hovering about the rocky cliffs at a 

 distance. I supposed that tliey were of this species, which is 

 recorded as breeding on this island, but I was unable to stop and 

 did not go near enough to identify them. I saw several about the 

 Pribilof Islands, but only one specimen was taken. I did not find it 

 on Walrus Island, where it is said to breed. 



Nesting. — Mr. Henry W. Elliott (1880), to whom we are indebted 

 for practically all that we know about the habits of the red-legged 

 kittiwake, says that it arrives on the fur-seal islands, for the purpose 

 of breeding, about the 9th of May and of its nesting habits he writes : 



It is much more prudent and cautious than the auks and the murres, for its 

 nests are always placed on nearly inaccessible shelves and points of mural 

 walls, so that seldom can one be reached unless a person is lowered down to it 

 by a rope passed over the cliff. Nest building is commenced early in May, and 

 completed, generally, not much before the 1st of July. It uses dry grass and 

 moss cemented with mud, which it gathers at the fresh-water pools and ponds 

 scattered over the islands. The nest is solidly and neatly put up ; the parents 

 work together in its construction most diligenty and amiably. Two eggs are 

 the usual number, although occasionally three will be found in the nest. If 

 these eggs are removed, tbe female will renew them like the "arrie" in the 

 course of another week or 10 days. 



Dr. L. Stejneger (1885) found the red-legged kittiwake breed- 

 ing abundantly in the Commander Islands, and says : 



Like its black-legged cousin, it only selects yteep and inaccessible rocks, and 

 in none of its habits at the breeding place could I detect any mai'ked differ- 

 ence. They also arrive at the islands about the same time, hatching their 

 young simultaneously with the other species. The two species usually keep 

 apart from each other. In the great rookery at Kikij Mys only one solitary 

 retl-legged bird was seen among the thousands and thousands of black feet, 

 while a still greater colony at Gavaruschkaja Buchta consisted of red legs 

 exclusively. On Copper Island, however, I found the two species breeding to- 

 gether on the same rocky wall — the black feet always higher up than the pres- 

 ent species. The two kinds were easily distinguished when lifting on the nests, 

 hrcvirostris having the gray of the mantle of a perceptibly darker shade than 

 polHcaris. 



