190 INSESSORES—CURSORES 
tent. In some instances they are so crowded upon 
the branches, as to cause them to give way; and 
when the young are fully fledged, and the place 
finally deserted, so great has been the havoe and de- 
struction they have caused, that what was before a 
flourishing forest is converted into a wilderness of 
dismantled trunks, every tree being as completely 
destroyed as if girdled, and the whole ground cov- 
ered with their excrements to the depth of several 
inches. 
But it is during their migrations that they assem- 
ble in the most astonishing multitudes. These mi- 
grations are performed only for the purpose of ob- 
taining food, and are not influenced by any changes 
in temperature, or the desire to seek a more genial 
climate. Such countless thousands of hungry birds 
must of necessity soon deprive a large tract of land 
of all its available resources; hence the necessity of 
their frequently changing their position. 
Audubon, speaking of one of these companies, 
says: “In passing over the Barrens, a few miles 
beyond Hardinsburg, I observed the Pigeons flying 
from northeast to southwest, in greater numbers than 
I thought I had ever seen them before; and feeling 
an inclination to count the flocks that might pass 
within the reach of my eye in one hour, I dismounted, 
seated myself on an eminence, and began to mark 
with my pencil, making a dot for every flock that 
passed. In a short time finding the task which I 
had undertaken impracticable, as the birds poured in 
in countless multitudes, I rose, and counting the dots 
