THE TRUE SWANS. 



■47 



black bill. It has long been naturalised in this country, and 

 has repeatedly hatched its young in captivity, so that there is 

 xihvays a strong probability of the cygnets escaping before they 

 •can be pinioned. Another North American species which 

 lias been stated — but on far weaker evidence— to have been 

 found at long intervals in the shops of Edinburgh poulterers, 

 is C. america?ius, a bird which is smaller than the Whoopcr, 

 though larger than Bewick's Swan, which it resembles in 

 having patches of small size at the base of the bill, but of a 

 deep orange-colour. In the adults of our Whooper and the 

 American Trumpeter Swan, the loop of the trachea between 

 the walls of the keel of the sternum takes a vertical direction, 

 whereas in Bewick's Swan and in C. ameriamus the bend is 

 horizontal; but in immature birds these distinctions are less 

 marked, and are not absolutely invariable." 



I. THE WHOOPER SWAN. CYGNUS MUSICUS. 



Anas cygmis, Linn. S. N. i. p. 194 (1766 ; pt.). 

 Cygnus imisicus, Macg. Br. B. iv. p. 659 (1852); Dresser, B. 

 Eur. vi. p. 433, pi. 419, fig. 4 (1880) ; B. O. U. List Br. 

 B. p. 120 (1883); Saunders, ed. Yarr. Br. B. iv. p. 308 

 (1885); Seebohm, Br. B. iii. p. 480 (1885); Saunders, 

 Man. p. 401 (1889); Lilford, Col. Fig. Br. B. part xxv. 

 {1S93) ; Sharpe, Cat. B. Brit. Mus. xxvii. p. 26 (1895). 

 {Plate LV. Fig. i.) 

 Adult Male. — White all over, with occasionally some ferrugin- 

 ous-yellow on the head ; "anterior part of the bill depressed and 

 black, the basal part, with the lores, yellow, this colour extend- 

 ing forward along each lateral margin of the upper mandible, 

 heyoiid the openings of the nostrils^ which are black ; the black 

 colour only reaches half-way to tl^.egape; legs, toes, and their 

 membranes black. Total length, about 5 feet; culmen, 4*2; 

 wing, 25-5 ; tail, 8*5 ; tarsus, 4*2 " {Salvadori). 



Adult Femak. — Similar to the male, but a little smaller. 

 Young Birds. — Greyish-brown; "beak first of a dull flesh- 

 colour, the tip and the lateral margins black, posteriorly black, 

 with a reddish-orange band across the nostrils, and with the 

 base and lores pale greenish-white" (^'(^r/z;^^/^;-/); "feet flesh- 

 colour" {Sa2nidc?-s). 



