BLACK SEA BBANT 239 



water, ponds ; others on islands in the Anderson, near its mouth ; and 

 many others either on the shore or on islands in Franklin Bay, or 

 other parts of the Arctic Sea. In some cases the nest was nothing 

 more than a mere depression lined with down; hut in some the 

 quantity of down was quite large. The number of eggs in a nest was 

 generally five; but in one case as many as seven were seen, and in 

 six or seven instances six" (Baird, Brewer and Ridgway, 1884, I, 

 p. 474). 



Writing from western Alaska, Nelson (1881, pp. 134-136) says: 



The flight of this species is peculiar among North American geese and 

 bears a close resemblance to that of the Eider and other species of heavy- 

 bodied short -winged Sea Ducks. It has a parallel in the flight of the Emperor 

 Goose except that the latter is a far heavier bird and, in consequence, the wing 

 strokes are less rapid. In B. nigricans the strokes are short, energetic, and 

 repeated with great rapidity, carrying the bird with a velocity far greater than 

 that attained by any other [American] Goose. ... 



The flocks . . . have a protean ability to change their form without ever 

 breaking the array or causing confusion. They are very gregarious and two flocks 

 almost invariably coalesce when they draw near each other. This frequently 

 occurs, until ... it results in a single flock numbering between four hundred 

 and five hundred birds. The usual size is considerably less, generally compris- 

 ing from twenty to fifty or more, and it is rare to see less than ten or fifteen 

 in a party. At times four or five individuals become detached and until they 

 can unite with a stronger party they fly irregularly about as though bewildered, 

 continually uttering their harsh notes, and hurry eagerly away to join the first 

 flock that comes in view. The order of flight is invariably a single rank, the 

 birds moving side by side in a line at right angles to their course so that the 

 entire strength of a flock is to be seen at a glance along its front, which, at 

 times, covers several hundred yards. There is barely room enough between 

 the individuals to allow a free wing-stroke. Thus ranged the flock seems gov- 

 erned by a single impulse, which sends it gliding along parallel and close to 

 the ground, then, apparently without reason, careering thirty or forty yards 

 overhead only to descend to its former level as suddenly as it was left; now 

 it sways to one side and then to the other, while at short intervals swift 

 undulations seem to run from one end of the line to the other. These move- 

 ments are repeatedly taking place. . . . 



The entire flock, consisting of perhaps over a hundred birds arranged in 

 single line, is hurrying on, straight as an arrow, towards its destination when, 

 without warning, it suddenly makes a wide curving detour of several hundred 

 yards, then resumes its original course only to frequently repeat the manoeuvre, 

 but always with such unison that the closest scrutiny fails to reveal the least 

 break or irregularity in the line; nor does the front of the flock swerve, except- 

 ing an occasional slight obliquity which is corrected in a few seconds. 



In addition to this horizontal movement is a still more interesting vertical 

 one which often occurs at the same time as the other but generally by itself. 

 A bird at either end of the flock rises or descends a few inches or several feet, 

 as the case may be, and the movement is instantly followed in succession by 

 every one of its companions till the extreme bird is reached and the entire 

 flock is on the new level; or, it may be that a bird near the middle of the line 



