larger than that of the family among the carnivores and the birds
of prey, though mostly being the result of their very modes of
feeding, can also be explained to some extent as a consequence of
the change produced in the animal world by the rapid increase of
mankind. At any rate it is worthy of note that there are species
living a quite isolated life in densely-inhabited regions, while
the same species, or their nearest congeners, are gregarious in
uninhabited countries. Wolves, foxes, and several birds of prey
may be quoted as instances in point.

However, associations which do not extend beyond the family
bonds are of relatively small importance in our case, the more so
as we know numbers of associations for more general purposes,
such as hunting, mutual protection, and even simple enjoyment of
life. Audubon already mentioned that eagles occasionally
associate for hunting, and his description of the two bald
eagles, male and female, hunting on the Mississippi, is well
known for its graphic powers. But one of the most conclusive
observations of the kind belongs to Syevertsoff. Whilst studying
the fauna of the Russian Steppes, he once saw an eagle belonging
to an altogether gregarious species (the white-tailed eagle,
Haliactos albicilla) rising high in the air for half an hour it
was describing its wide circles in silence when at once its
piercing voice was heard. Its cry was soon answered by another
eagle which approached it, and was followed by a third, a fourth,
and so on, till nine or ten eagles came together and soon
disappeared. In the afternoon, Syevertsoff went to the place
whereto he saw the eagles flying; concealed by one of the
undulations of the Steppe, he approached them, and discovered
that they had gathered around the corpse of a horse. The old