132 
BIRD-LIFE. 
however, others among the numerous feathered tribes 
which are very highly gifted. According to Faber, 
the old story of the Raven getting at the flesh of 
crustaceous animals, by letting them fall from a height 
on to the rocks below, is certainly no fable. Spaniards 
assert that the Lammergeir, whose food principally consists 
of large bones, breaks them in the same manner ; whence 
they have given the bird the title of “ Bone-smasher.” I 
myself have often observed this bird rise, time after time, 
from a rock, and descend again, as though it were 
occupied in taking something up in the air and letting it 
fall again; and this, to me, otherwise inexplicable pro¬ 
ceeding, strengthens my belief in the above assertion. 
Parasitical birds depend on the weakness or carelessness 
of other birds to take their prey. A Kite (Milvus parasi¬ 
ticus), common in the East, pesters Falcons, Eagles, and 
such like, with such bold importunity, that these throw 
them a portion of their booty. The Skuas persecute 
other Gulls to such an extent that they are forced to 
throw up the prey they have swallowed, which the 
former immediately pounce upon. Gannets and Terns 
do the same. These pirates readily distinguish those 
birds which they can plague with impunity from those 
which do not yield to their persecutions. When several 
different species are to be seen living together, and each 
has to look sharp after his food, one finds numberless 
opportunities of observing how they seek to over-reach 
one another. The Laughing Gulls, in the Hamburg 
Zoological Gardens, which are allowed their liberty, keep 
a regular watch over the diving Ducks, and often rob 
them of their booty as soon as they rise to the surface. 
They narrowly observe those that dive, awaiting the 
instant of their return to the surface, at which moment 
