294 TACHYERES CINEREUS 



Flight. The question of the flying powers of this duck has already been dis- 

 cussed at some length. It remains to say something of their curious habit of racing 

 over the water when pursued. This is characteristic of the species and has aroused 

 the wonder of all who have ever seen it. The birds go off at a remarkable speed, 

 churning the water and giving very much the impression of a little "side-wheeler." 

 In this performance the wings and feet undoubtedly both play a part, the wings 

 being used to keep the body up and both wings and feet being responsible for the 

 churning of the water (Nicoll, 1908). The speed attained by this method is quite 

 remarkable. The older writers (Cunningham, 1871, e.g.) found that they could not 

 be overtaken with a boat, however well manned, and they estimated the speed at 

 twelve to fifteen miles per hour. Beck (MS.) notes that while pursuing them in a 

 launch going eight miles per hour the birds gained for a time, but after about a mile 

 they would begin to weaken and would soon be exhausted. The wings are not moved 

 alternately, as Darwin thought, but simultaneously as in any other bird, although 

 the great splashing gives the appearance of uneven locomotion. Vallentin (1904) 

 thought that when the bird was suddenly alarmed it could really use its wings 

 alternately and he even made some experiments on living birds! 



These ducks are rarely seen in large aggregations. Pairs or small groups numbering 

 from four to fifteen are the usual thing, though on occasion larger companies, such as 

 forty-two (Blaauw, 1921), seventy-four (Beck, MS.) and even many hundreds (Cun- 

 ningham, 1871) have been seen together. In the Falklands the young, after they 

 are fledged and separated from their families, pack in large flocks (Vallentin, 1904). 



Association with other Species. There are no other sea ducks in the region 

 of the South Atlantic and the bird has the ocean pretty much to itself, although it 

 is frequently seen near cormorants and gulls (Beck, MS.) and the Great Southern 

 Grebe (Crawshay, 1907). 



Voice. The note usually heard from the Steamer Duck is a hoarse, low snoring 

 call, like that of a bull-frog, uttered rapidly. It has also been likened to the grunt 

 of a domestic pig, but higher pitched. These notes are generally attributed to the 

 female (Cunningham, 1871; W. S. Brooks, MS.), though Vallentin (1904) says they 

 are uttered by the male at the approach of danger. Brooks described the female's 

 note as a "hoarse low sort of snoring call, rather suggesting the leopard frog of New 

 England, only uttered rapidly sometimes, and with considerable spirit." The male, 

 William Percy says, has a variety of notes, the most frequent being a shrill qu-i-e-u-ll 

 repeated about twenty times after which there is a quick kek-kek-kek-kck. This last 

 is sometimes left out altogether. Brooks describes it as "a wheezy sneeze or cough, 

 something like kee-u-kee-u-kee-u." 



The trachea of the male is furnished with a large bony box on the (left?) side 

 (Cunningham, 1871a; see also Eyton, 1838, pi. 2, fig. 2). 



