MUTE SWAN 85 
DESCRIPTIVE CHARACTERS. 
PLUMAGE. Adult male nuptial.——Pure white. 
Adult female nuptial.—Similar to the male in plumage. 
Adult winter, male and female.—Similar to the nuptial 
plumage. 
Immature, male and female (cygnet).—Greyish-brown, 
the breast and abdomen being of a lighter shade. 
Brak. Deep orange colour, except the ‘nail,’ the nos- 
trils, and the ‘ basal protuberance,’ which are black. There 
is also a noticeable patch of black, extending from the 
front of the eye to the base of the beak. 
Fret. Black. 
TrivEs. Blackish-brown. 
AVERAGE MEASUREMENTS. 
TOTAL LENGTH Sees in. Female smaller. 
WING ... se SS RL ATi n 
IDnAK ... f ae LS Ae 
TARSO-METATARSUS ... 4:5 
Eee 4x 9: 9 in. 
Note.—The Mute Swan is the only one of the three 
species mentioned, which carries its neck with a graceful 
sigmoid curve, its wing-plumes at the same time being 
raised and arranged loosely over the back. The whole 
carriage of the bird is one of pride and dignity. 
The Whooper and Bewick’s Swans, on the other hand, 
assume a stiffer gait; they move on the water lke Geese, 
with necks straight and backs flattened. 
In the Mute Swan there is no cavity in the upper part 
of the breast-bone (sternum) to receive a coil of the wind- 
pipe (trachea). In the adult Whooper the loop of wind-pipe 
takes a vertical course, in Bewick’s, a horizontal course, as 
it hes in the sternal cavity. 
The so-called ‘Polish’ Swans are now looked on as 
white varieties of the cygnet of the Mute Swans (‘ Zoolo- 
gist,’ 1887, p. 4638, 1888, p. 470, also Cat. B. Brit. Mus., 
XXvil, p. 38) (Saunders). 
