iJtc B'lrtls uf Ncjamiluntl. 367 



explanation of tliis failure of tlie \vatcr-sup[)ly of the lake is 

 to be found in tlie fact tliat one of the many large cliannels 

 of the Okavango River, called the Teoughe, which formeily 

 ran into the lake at the N.W. corner, has gradually become 

 choked by a natural process of reed-growth and silting-up. 

 Now no water at all finds its way into the lake from the north- 

 west, and its only source of supply is the south-east corner, 

 where it is connected with the Botletle by a kind of back- 

 water or arm through which it receives a certain amount of 

 water when the floods in the Botletle have risen sufficiently 

 high for water to run back along this channel. Living- 

 stone wrote of this back-water that it had never been ob- 

 served to flow either way and was as stagnant as the lake 

 itself, but this is not the case at the present day. At the 

 time of our departure from Ngamiland in October water was 

 running into the lake with considerable current and volume, 

 but the lake never fills now to anything like its former level. 



From the ornithological point of view we found Ngamiland 

 rather disappointing. Even the Avater-birds (Ducks excepted) 

 were not observed in such numbers as we had been led to 

 expect from the descriptions of other travellers, and I can only 

 remember seeing two Pelicans during the whole of our stay. 

 However, there is no doubt that the date of our visit, which 

 was Avhile the inundation was rising (the dry season), was not 

 the best time to see the birds. It is during the rains (October 

 to March), when the floods are subsiding, that such vast 

 quantities of water-fowl are attracted to feed on the flats. 

 The Marabou Storks were beginning to appear in parties 

 when we were obliged to leave in October. 



Ducks were always to be seen, often in incredible numbers, 

 flighting in the evenings. By far the most numerous species 

 was the Pink-billed Teal, and next the Cape Pochard. The 

 Yellow-billed Duck was not very common. Hottentot Teal 

 were met with in small numbers throughout the marshes, 

 and the White-faced Tree-Duck was often found in large 

 flocks. It is curious that we did not see a single specimen 

 of the Cape Shoveler in Ngamiland, nor did we notice any 

 Egyptian Geese. The Knob-billed Duck was in fair numbers, 

 and the Pigmy Goose was very plentifiil on the Tamalakau 



