104 
WILD BEASTS AND THEIR WAYS 
CHAP. 
owing to the greater distance it has been forced to 
travel. All these birds have been necessarily 
directed by sight, and not by the sense of smell. 
The sense of vision may be continually observed 
by any person who has experience of countries that 
are full of living creatures. When the grass is fired 
in the dry season, there may not be a bird in sight, 
but directly that the dense volumes of black smoke 
darken the air with rolling clouds upon the earth’s 
surface, a great variety of birds are almost immedi¬ 
ately attracted. The buzzard, the fly-catchers, 
and, curiously enough, the bustard (or houbara), 
which is generally so scarce, all appear upon the 
dusky scene, and challenge the smoke and flames, 
to pursue the locusts, which are endeavouring to 
escape from the advancing fire. 
The so-called rhinoceros bird, which is supposed 
to afford the animal some notice of approaching 
danger, is not confined specially to that particular 
beast, but it is to be seen frequently picking the 
ticks and other vermin from the backs and sides of 
buffaloes, as starlings may be seen upon the cattle in 
England during the warm days of summer. There 
is also a so-called crocodile bird, which is accredited 
with watchful instincts in the interest of the animal 
it attends upon; this is the ordinary plover, which 
when alarmed cries in good English, throughout the 
world, “ Did-he-do-it ? Did-he-do-it ? ” These 
birds are not employed in protecting the animals 
they wait upon, but they are simply searching for 
insects which infest such creatures, and when 
