crab.
This Crustacean dwells in the empty shells of Gasteropods. At the
least alarm he retires within this shell and becomes invisible, but
the bird advances with so much precaution that he is often able to
seize the crab before he has time to hide himself. If the raven fails
he turns the shell over and over until the impatient crustacean allows
a claw to emerge; he is then seized and immediately devoured.

[15] Huber, _Nouvelles Observations sur les Abeilles_,
t. ii. p. 291.

If there is a question of hunting larger game like a Hare, the Raven
prefers to take an ally. They start him at his burrow and pursue him
flying. In spite of his proverbial rapidity the hare is scarcely able
to flee more than two hundred yards. He succumbs beneath vigorous
blows on his skull from the beaks of his assailants. During winter, in
the high regions of the Alps, when the soil is covered with snow, this
chase is particularly fruitful for ravens. The story is told of that
unfortunate hare who had hollowed out in the snow a burrow with two
entrances. Two of these birds having recognised his presence, one
entered one hole in order to dislodge the hare, the other awaited him
at the other opening to batter his head with blows from his beak and
kill him before he had time to gain presence of mind.[16]

[16] F. von Tschuedi, _Les Alpes_, Berne and Paris, 1859.

Rooks sometimes hunt in burrows by ingeniously-concerted operations.
Mr. Bernard[17] has described the interesting way in which the Rook
hunts voles or field-mice in Thuringia. His curiosity was excited by
the way in which numerous rooks stood about a field cawing loudly. In
a few days this was explained: the field was covered with rooks; the
original assemblage had been calling together a mouse-hunt, which
could only be successfully carried out by a large number of birds
acting in conjunction. By diligently probing the ground and blocking
up the network of runs, the voles, one or more at a time, were
gradually driven into a corner. The hunt was very successful, and no
more voles were seen in that field during the winter.

[17] _Zoologist_, October 1892.

_Coursing._--Other animals are not easily discouraged by the swiftness
of their prey; they count on their own resistance in order to tire the
game; some of them also manage their pursuit in the most intelligent
way, so as to preserve their own strength while the tracked animal's
strength goes on diminishing until