The Food of Birds 153 
old birds and the more advanced young following the 
locusts.” 
Slugs and snails are eaten by thrushes and many other 
small birds with avidity, and the name ‘Snail-hawk” 
has been given on account of one bird’s fondness for these 
mollusks. The Oyster-catcher feeds on clams and oysters 
and derives its name from the facility with which it in- 
serts its bill and pries open the shells. The Courlan, 
a near relative of the rails, feeds on clams and mussels 
and has a most ingenious method of obtaining its food. 
In shallow water it feels about with its feet for these 
mollusks, and when they are found the bird inserts its 
bill between the valves with a sudden quick stroke, and, 
thus suspended, the heavy shell and its occupant are 
carried to the shore, where the shell is forced open and 
the animal eaten. Crows treat shell-fish in the same 
way that they do sea-urchins and crabs, carrying them 
aloft and, after dropping them, descending to feed 
on the nutritious flesh exposed by the shattered 
shells. 
Squids, the “head-footed” leaders of the division of 
mollusks, are eaten by penguins at least, and so numerous 
and at times so conspicuous a feature of marine life are 
they that probably many other birds also feed upon 
them. Even deep-water snails and crabs are not safe, 
as the sturdy sea-ducks will sometimes dive to a depth 
of one hundred and fifty feet to feed upon them. 
Fish count many enemies among birds, which have 
numerous ways of obtaining their victims from ocean or 
lake. Some of these are so ingenious that they well 
