XVII 
THE CROCODILE 
221 
see the bird engaged in such an interesting occupation 
but without success, and I have never met with a 
hunter or traveller who has seen it at this work. Even 
Livingstone during the whole time he was in Africa 
“ never witnessed this friendly act.” The boatmen on 
the White Nile point out a plover which they call 
Ghaffir (watchman) for the following reason : When a 
The Plover {Pluvianus cegypticus) is as useful to crocodiles as the 
oxpecker to cattle and kudus. This plover was known to 
Herodotus, who refers to it as the Trochilus. 
boat approaches crocodiles lying on the banks or sand- 
spits, the bird flies up twittering and warns the sleeping 
reptiles. The buff-backed heron {Bubulcus lucidus), 
sometimes called the cow-heron, picks leeches, &c., 
from crocodiles as well as ticks from cattle and 
elephants. 
These dutiful birds are useful ; for whilst hunting 
