THE RUDDY SHELU-DUCK-S. 
263 
I. THE RUDDY SHELD-DUCK. CASARCA CASARCA. 
Anas casarca, iTnn. S. N. iii. App. p. 224 (1768). 
Tadorna casarca, Macg. Br. B. y. p. 19 (1852); Dresser, 
B. Eur. Yi. p. 461, pi. 421 (1875); B. 0 . U. List Br. B. p. 
122 (1883); Saunders, ed.Yarr. Br. B. iv. p. 347 (1885) ; id. 
Man. p.409 (1889); Lilford,Col. Fig. Br. B. part xx. (1891). 
Tadorna rutila, Seebohm, Br. B. iii. p. 524 (1885). 
Casarca rutila, Salvad. Cat. B. Brit. Mus. xxvii. p. 177 (i 89 S)- 
Adult Male.— General colour above tawny-che.stnut ; the wing- 
coverts paler and of a light fawn-colour, with white bases ; 
bastard-wing, primary-coverts, and quills black; secondaries 
black internally, externally bronzy-green with a coppery gloss, 
the inner secondaries externally deep chestnut, ashy on the 
inner webs ; lower back pale tawny, vermiculated with dusky- 
erey ; rump, upper tail-coverts, and tail black, with a greenish 
gloss ; under surface of body dark tawny, deepening into chest- 
nut • 'under wing-coverts and axillaries white; the head and 
neck also tawny^ but the crown paler and inclining to white, 
as also the lores ; round the neck a black collar ; bill black ; 
feet black somewhat brownish on the toes and tarsus ; iris 
black. " Total length, 25 inches; culmen, 17; wing, 14-5; 
tail, 4'9 ; tarsu.s, 2'2. _ , , , , 
Adult remale.— Smaller than the male, and wanting the black 
collar; the head, face, and wing-coverts whiter ; bill black ; feet 
brown, blackish on the joints and black on the webs, except 
at the junction with the toes ; iris deep brown. Total length, 
22-5 inches; wing, 13-5. . 
There seems to be but little difference in colour between 
the summer and winter plumages of the Ruddy Sheld-Duck, 
but the feathers have sooty-brown centres in summer, and 
during the winter the black ring round the neck is absent, 
while the buff tinge on the wing-coverts is also probably a sign 
of the breeding-season, as these are white in many birds killed 
in the winter. 
Young Birds. — Resemble the female, and have no black 
collar ; they are also more dingy in colour. 
Characters.— Besides the generic features given above, the 
general tawny-colour of the bird and its size serve to dis inguish 
it from the other Ducks. 
