_Killer Whales_
Whales, by virtue of their size and speed, are not preyed upon by other
animals. The killer whale, however, has the size and inclination.
Generally, it is content to capture seals, sea birds, and fishes, and it
does not range too far from this prey. There have been isolated reports
of killer whales attacking the gray whale. The gray whale is described
as being very disturbed whenever a killer whale appears. On the coast of
Siberia the gray whale will hide in very shallow water and if cornered
is said to go into shock, floating at the surface, stomach up, while the
killer whale bites at the tongue and flippers. Perhaps reports like this
have been improperly interpreted. It is easy to understand how killer
whales would congregate around the catch of the whaler. Recently studies
on the loss of hooked tunas from the long-line fishery of the Japanese,
show that killer whales are adept at stealing fish along the setline.
Additional studies on the natural history of the killer whale must be
made before its relationship to other whales can be properly assessed.
_Parasites_
If whales generally lead a charmed life with respect to predators, they
still have their share of parasites both external and internal. Their
huge bodies are ideal platforms for the growth of barnacles which have
specialized for this unusual habitat. Another very annoying skin
parasite is the whale louse, which is a flattish small crustacean which
clings by claws to the delicate skin. The digestive tract of the whale
provides a wonderful habitat for round worms and tapeworms. Like their
host, these parasites are the largest of their kind. Other organs such
as the kidneys, liver and lungs are infested too.
Sperm whales suffer from another affliction which is an obstruction of
the intestine by a fatty concretion which forms from the bile.
Ordinarily these are passed from the digestive tract when small, but if
they are retained and continue to grow, an obstruction is possible. The
material is a grayish wax which is known as ambergris. It is used by the
perfume industry to make permanent blends of various fragrances. Most of
this material is obtained by whalers when they process the sperm whale.
Only rarely does the material float ashore after the death of the
unfortunate producer. Nowadays the value of ambergris is but moderate.