Whales are found with healed broken bones which must have been incurred
by fighting and other collisions. The skin of whales is mottled with
scars which were produced by parasites and by fighting. Toothed whales
are especially scarred from the raking by the teeth of an adversary
during battles for dominance. For at least 5 centuries, man has preyed
on the whale. In recent times navies of several nations have been
alarmed by unidentified underwater objects which cannot easily be
distinguished from submarines. Some of these contacts are produced by
whales. The counter measures not only cost the whale its life, but also
causes the navies unnecessary expenditures of depth charges and time,
and produce considerable tension and anxiety.