338 BIRDS OF DAMABA LAND. 



388. Dendrocygna viduata (Linn.). Widow Tree-Duck. 



Canard du Maragnan, Buffon's PI. Enl. pi. 808, vol. x. p. 106. 

 Dendrocygna viduata, Layard's Oat. No. 650. 



,, „ Chapman's Travels in S. Afr., App. p. 423. 



„ „ Finscli & Hartlaub's Vogel Ost-Afrika's, 



p. 806. 



This Duck, which congregates in immense flocks, is 

 exceedingly common in the Lake-regions and on the 

 river Okavango; in the latter locality it is seen most 

 abundantly during the annual inundation, when much 

 of the usually dry land which abuts upon the river is 

 converted into marshes and swamps. As these tempo- 

 rary resorts dry up, the Ducks of this species move 

 eastward until they arrive at that extensive flooded 

 country which stretches far and wide on each side of the 

 Teoughe below Libebe. 



I have never seen this Duck in Damara or Great 

 Namaqua Land. 



The iris is dark brown ; the upper mandible of the 

 bill black, darkest on the nail, which is surrounded by 

 a livid blue patch, a similarly coloured spot being 

 situate in front of each nostril ; the lower mandible 

 black, mingled with brown and livid blue ; the legs and 

 toes bluish lead-colour, tinged with brown on the upper 

 surface ; the webs a shade darker than the toes. 



Measurements of a male : — 



in. lin. 



Entire length 17 9 



Length of folded wing 9 



„ tarsus . 2 3 



„ middle toe 2 7 



„ tail 3 



hiU 2 .3 



