56 BULLETIN 130, UNITED STATES NATIONAL MUSEUM 



BehaA)ior. — Mr. Millais (1913) describes the flight of this species 

 as follows: 



The, beautiful markings of the male of this species are only noticeable when 

 the observer is close at hand, so that they are not the easiest duck to identify 

 except when in flight. The flight, at first somewhat laborious, is very rapid. 

 The short, pointed wings are beaten swiftly, and the bird constantly swings 

 from side to side, even more frequently than the long-tailed duck. The eleva- 

 tion is moderately high, performed at an altitude similar to the goldeneye, 

 but when passing up or down stream it zigzags and turns, to accommodate its 

 line to every bend of the stream, however slight. The harlequin never thinks 

 of cutting off corners, and it would seem that it imagines its life depends 

 on keeping exactly over the water, however much it bends or twists. I have 

 seen harlequins fly religiously above a bend in a stream that formed almost 

 a complete circle in its course, and yet the birds did not cut across it to 

 shorten their route. 



I have watched harlequin ducks in flight many times and have 

 shot quite a few of them, but I never noticed any swinging from 

 side to side, as referred to above, and several writers have re- 

 ferred to their flight as straight. They usually fly close to the 

 water and often in such compact flocks that a large number may be 

 killed at a single shot. They also swim in close formation, some- 

 times with their bodies almost touching. 



Walter H. Kich (1907) says: 



If a shot is fired at a flock on the wing they will sometimes plunge from 

 the air into the water and after swimming below the surface again take wing, 

 coming up a hundred yards away — seeming, the instant they reappear, to 

 dash from the depths into the air at full speed, leaving the gunner inexperienced 

 in their ways, and who perhaps had thought that by some miraculous chance 

 he had killed the entire flock, to find that he doesn't care for that kind of duck 

 after all. I passed through just such an experience once, and remember 

 yet how disgusted and surprised I was when after steaming up to where the 

 whole flock should have been dead — no duck — and what may have been their 

 ghosts rising from their watery graves 60 yards away. 



Harlequin ducks are fond of feeding in rough water along rocky 

 shores or in the surf just off the beaches, where they ride the waves 

 lightly and dive through the breakers easily and skillfully. They 

 dive so quickly that they often escape at the flash of a gun. In 

 diving the wings are usually half opened as if they intended to 

 use the wings in flight under water, which they probably do. 



The peculiar whistling note of this duck has been likened to the 

 cry of a mouse, whence it has been called the " sea-mouse " on the 

 coast of Maine. Mr. Bretherton (1896) describes it as "'a shrill 

 whistle descending in cadence from a high to a lower note, commenc- 

 ing with two long notes and running off in a long trill."'' Mr. Mil- 

 lais (1913) writes: 



When first arriving at the breeding grounds in flocks in early May they 

 are very restless, constantly flying to and fro, whilst the females utter their 



