138 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB. 



As if they were satisfied with the musical character of their wings, they 

 are, with us certainly, very abstemious as regards mouth music. I have never 

 heard them utter a sound. 



An interesting sight is a flock of Whistlers inside the lines of surf off the 

 beach at Ipswich. Just before the wave breaks over them, they dive, coming up 

 on the other side. Their courtships begin the last of March and the water 

 foams about their white flanks as the males chase each other. 



The adult males are always in the minority at Ipswich as compared with 

 the females and immature birds. Curiously enough the reverse of this seems 

 to be the case in the Back Bay basin of the Charles River, at Boston. Thus on 

 Christmas day, in 1902, I counted eighty Whistlers in this basin, and of these, 

 sixty were adult males. 



Either the spring moult in some takes place very late, or more than one 

 year is needed to attain full adult male plumage. Thus a young male in my col- 

 lection, shot at Ipswich on April 3d, 1904, is as large as the adult male, but 

 resembles the smaller female in plumage, except that it is lighter gray on the 

 upper back, the upper breast is nearly white, and the head is an ashier brown 

 with here and there a scattering of black, but not iridescent, feathers. The 

 testicles were not enlarged. 



The measurements of an adult male and female and of two immature 

 males in the spring, in my collection are here given in inches : — 



On May ist I watched with the glass several young males in a flock of 

 thirty Whistlers off Ipswich Beach. Several of these were destitute of white 

 spots, while others had faint ones. Their mottled rather than snowy white 

 sides and brown heads easily distinguished them from the adult males, and their 

 large size from the adult females. 



At a distance, the Whistler may be recognized by the whistling sound made 

 in flying by the rapidly vibrating wings, and by the short chunky form with 

 large head held slightly up. The shape is very different from that of the 

 Red-breasted Merganser although both have large white patches on the wing. 

 The Merganser has a long and narrow neck, head, and bill, which it holds 

 straight out in front. The adult male Whistler on the water is a beautiful sight 

 with his greenish black head, round white spot close to the bill, and snowy white 



