194 BIRDS OF TUNISIA 



CYGNUS OLOR (J. F. Gmelin). 

 MUTE SWAN. 



Anas olor, Gmd. Syst. Nat. i, p. 501 (1788). 



Cygnus olor, Vieill. Nouv. Diet, ix, p. 37 (1817) ; Salvadori, Cat. Birds 



Brit. Miis. xxvii, p. 35 ; Malhcrbc, Cat. Rais. d'Ois. Alg. p. 22 (1846) ; 



Loche, Expl. Sci. Alg. Ois. ii, p. 352 (1867); Koenig, J. f. 0. 1888, 



p. 285; id. J.J. 0. 1893, p. 95. 



Z)escr(p/;o«.— Adult male, ^Yintel^ from Italy. 



Entire plumage pure white. 



Iris brown ; greater part of the bill orange-red ; bare loral space, base and 

 edge of the mandibles, nail, nostrils, and a protuberance or tubercle on the 

 forehead black ; feet black. 



Total length 55 inches, wing 26, culmen 3-60, tarsus 4. 



Adult female, similar to the male, but rather smaller, with a more 

 slender neck, and with a smaller frontal tubercle. 



Young smoky-grey, with lead coloured bill and feet. - 



Observation. — Cygnets in down of domesticated Mute Swans are usually 

 of a grey colour, but not invariably so, and I had a pair of Swans in my 

 garden, which one year produced a brood of four young, two of the ordinary 

 grey colour, the other two of a creamy-white colour. In other years the 

 progeny of this pair of Swans used always to be grey. 



In the so-called "Polish Swan" {C. immutabilis, Yarrell), now generally 

 considered as a mere variety of the present species, the cygnets are said 

 to be always white. 



Although I have no personal knowledge of the occurrence in 

 Tunisia of either this or the following species of Swan, I include both 

 among the birds of that country, as Wild Swans are undoubtedly to be 

 met with in winter in the Eegency, and Loche, when stating that 

 both species are to be found on all the large lakes of Algeria, adds 

 that they are much commoner in Tunisia (Expl. Scient. Alg. Ois. ii, 

 p. 356). 



According to Loche, besides the individuals of the present species, 

 which are resident (presumably in a semi-domesticated, and not 

 in a feral state), considerable numbers may sometimes be met with 

 on some of the Algerian lakes, during the periods of migration and 

 particularly in very severe w^inters. Favier states that this Swan 



