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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 (Plwricutus crgypticus) 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 lucidias], 

 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 



