rowling wolf and the fox; the
racoon and the cougar; the lynx and the great black bear.

With so many enemies, one would think that the "passengers" would soon
be exterminated. Not so. They are too prolific for that. Indeed, were
it not for these enemies, they themselves would perish for want of food.
Fancy what it takes to feed them! The flock seen by Wilson would
require eighteen million bushels of grain every day!--and it, most
likely, was only one of many such that at the time were traversing the
vast continent of America. Upon what do they feed? it will be asked.
Upon the fruits of the great forest--upon the acorns, the nuts of the
beech, upon buck-wheat, and Indian corn; upon many species of berries,
such as the huckleberry (_whortleberry_), the hackberry (_Celtis
crassifolia_), and the fruit of the holly. In the northern regions,
where these are scarce, the berries of the juniper tree (_Juniperus
communis_) form the principal food. On the other hand, among the
southern plantations, they devour greedily the rice, as well as the nuts
of the chestnut-tree and several species of oaks. But their staple food
is the beech-nut, or "mast," as it is called. Of this the pigeons are
fond, and fortunately it exists in great plenty. In the forests of
Western America there are vast tracts covered almost entirely with the
beech-tree.

As already stated, these beechen forests of America remain almost
intact, and so long as they shower down their millions of bushels of
"mast," so long will the passenger-pigeons flutter in countless numbers
amidst their branches.

Their migration is semi-annual; but unlike most other migratory birds,
it is far from being regular. Their flight is, in fact, not a
periodical migration, but a sort of nomadic existence--food being the
object which keeps them in motion and directs their course. The
scarcity in one part determines their movement to another. When there
is more than the usual fall of snow in the northern regions, vast flocks
make their appearance in the middle States, as in Ohio and Kentucky.
This may in some measure account for the overcrowded "roosts" which have
been occasionally seen, but which are by no means common. You may live
in the west for many years without witnessing a scene such as those
described by Wilson and Audubon, though once or twice every year you may
see pigeons enough to astonish you.

It must not be imagined that the wild pigeons of America are so "