Nelson on the Black Bra/it. 1 35 



and repeated with great rapidity, carrying the bird with a velocity 

 for greater than that attained by any other Goose with which I am 

 acquainted, though probably its eastern prototype equals it in this 

 respect. 



But this is not the point upon which the mind rests when the 

 birds are in view, for then the eve is held in involuntary admira- 

 tion of the varied and graceful evolutions of the flocks which 

 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 eaeh 

 other. This frequently occurs until, as I have seen, it results in 

 a single flock numbering between four hundred and five hundred 

 birds. The usual size is considerably less, generally comprising 

 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 de- 

 tached 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 governed 

 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 movements are re- 

 peatedly taking place; they are extremely interesting to observe 

 but difficult. I fear, to convey an adequate idea of in words. 



The entire Mock. c< nsisting of perhaps over a hundred birds 

 arranged in single line, is hurrying on. straight as an arrow. 

 toward 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 maneuvre, but 

 always with such unison that the closest scrutiny fails to re- 

 veal the least break or irregularity in the line : nor does the front 

 of the flock swerve, excepting an occasional slight obliquity 

 which is corrected in a few seconds. 



