CHAULELASMUS STREPERUS 203 



Description. — Adult male, winter, from North Tunisia. 



General colour of upperparts brownish-grey, the feathers of the mantle 

 and back barred and pencilled with narrow wavy white lines ; lower back, 

 rump, and upper tail-coverts black ; tail brown ; primaries brown ; darker on 

 their outer webs and tips ; secondaries greyish-brown on their inner webs, 

 and pure white on their outer webs, presenting a conspicuous alar patch ; 

 greater upper wing-coverts mostly black ; median wing-coverts mostly chest- 

 nut ; lesser coverts grey-brown ; an indistinct whitish collar; breast-teathers 

 marked with alternate crescent-shaped lines of dark grey and white, 

 darker above and lighter below ; abdomen white, becoming pale grey on the 

 crissum ; flanks pencilled with grey and white ; under tail coverts black. 



Iris brown, bill dull yellow, blackish on the rib of upper mandible ; feet 

 dull orange. 



Total length 21 inches, wing 11, culmen 2, tarsus 1-50. 



Adult female, general colour above brown, the back mottled with 

 rufous crescent-shaped markings ; rump blackish ; tail brown, barred and 

 margined with dull white ; wing like that of the male, but with the chestnut 

 colouring less pronounced; throat and neck whitish, speckled with brown; 

 breast mottled with rufous-brown, and with crescent-shaped whitish bars 

 and margins to the feathers ; abdomen white ; flanks and crissum whitish 

 mottled with grey ; under tail- coverts whitish. 



Soft parts as in male, measurements rather less. 



The adult male in summer assumes a plumage resembling that of the 

 adult female, but the alar speculum is always whitish, and its larger size 

 and other differences are distinguishing characters. 



The Gadwall is a winter visitor in Tunisia, arriving together with 

 other species of Duck in October and November, and leaving again 

 in February and March. Although not rare, it can hardly be called 

 common in the liegency, and appears to be somewhat irregular in its 

 appearance, being more plentiful in some years than in others. 

 Loche, Salvin and Canon Tristram all record its occurrence in Algeria, 

 and it seems to be fairly abundant on Lake Fetzara and near Constan- 

 tine ; but according to Favier, it is scarce near Tangier, and irregular 

 and uncertain in its appearance. The same may be said regarding 

 the occurrence of the species in Italy, and perhaps generally in the 

 Mediterranean. 



This Duck prefers marshes and fresh water lakes to the sea coast, 

 is gregarious and associates with other species of water-fowl, as well 

 as with its own kind. It flies, swims, and dives well, but as a rule 

 rcimains hidden during the day time, and feeds principally during the 

 early morning and late evening hours. Its food consists of the seeds 



