WHITE-WINGED SCOTER 329 



the smallest \3/ 8 inches, while the remains of three scallops of similar 

 size were found in its gizzard. Mussels of over 2i/ 2 inches have been 

 found in the gullets of these ducks. Diving ducks sometimes meet their 

 death by having the mussel they are attempting to swallow clamp onto 

 their tongue or bill and so cause them to drown. 



These birds have some habits unlike those of other ducks. J. M. 

 Edson, in notes quoted by Bent (1925), says that during the summer, 

 particularly if the weather be pleasant, and usually in the late after- 

 noon, they have a habit of leaving the water and taking a flight over- 

 land; the birds rise in considerable flocks to an elevation of 200 or 300 

 feet, stringing out in line or in converging lines, sometimes forming a V. 

 The flights are of short duration, and after a little while the flocks may 

 be seen returning to resettle on the water offshore. He records another 

 instance of the peculiar behaviour of these scoters: "Watching the sea 

 birds from a bluff . . . on a calm evening in December (the 24th), my 

 attention was attracted by unusual activity in a little group of White- 

 winged Scoters. . . . Ten of these birds were bunched together and 

 actively swimming and plunging about within a circle of perhaps 10 or 

 12 feet in diameter. I was unable to distinguish the sexes with certainty, 

 and have no knowledge to the effect that December is their courtship 

 season. It looked like a game of tag of some sort. At the center of the 

 group two birds would assume a pose as if billing and caressing each 

 other, one with its head elevated, the other's depressed, the bills coming 

 in contact. The pose would last only two or three seconds, till some 

 other bird would approach one of them from behind, then the latter 

 would suddenly turn upon it and chase it away, the pursued bird taking 

 a circular course around the flock. Sometimes both the posing birds 

 w r ould be simultaneously approached, and each would turn upon his as- 

 sailant. The other birds would hover close about, watching for a chance 

 to tag the posers from behind. The two main actors would again come to 

 the center and resume their pose, only to be promptly interrupted again 

 with the same result. ... I watched them for perhaps half an hour, and 

 the game was still in progress when I left." Again in February Edson 

 saw the same performance enacted by about the same number of birds 

 and the play was as before. 



In spring the flight northward along the Atlantic coast commences 

 early in March and is at its height in the first half of May. In addition 

 to this northward movement, a western overland flight takes place 

 during May. This flight is composed entirely of adult birds that breed in 

 the Canadian interior, and which do not seem to heed the northward 

 movement of the others of their kind. Instead, they gather in large 

 flocks of several thousands until the time arrives for their departure, 

 which is usually about the 12th or the 15th of May. In autumn, on 

 the Atlantic coast, some flocks appear during the latter part of August 

 and throughout September, but the main flight takes place in October. 

 Winter, on the Atlantic coast, is spent from the Gulf of St. Lawrence to 

 South Carolina, with the centre of the winter range on the waters of 



