_Evolutionary Place_
It should be kept in mind, however, that this whale is the most
primitive of the living baleen-bearing whales, and it seems to represent
the point in the evolutionary sequence from which the two main groups
diverged. The California gray whale is the sole survivor of a family of
whales which in past eons was represented by many species. It has a
smallish head with a limited filtering mechanism. Its dependence on
foods which are found only near to shore is considered further evidence
that it is primitive. Likewise its need for harbors to calve suggests
that it has not lost its dependence on the nearshore habitat, even
though it can safely cross the wide Pacific. The extremely restricted
and separated distribution pattern of the whale is typical of an old,
primitive species which persists either in its preferred ancestral home,
or which occupies less desirable habitats into which it was forced by
the more successful species. Recently gray whale remains were found in
the Netherlands, and it is possible that it was exterminated in European
waters by prehistoric whaling prior to the Ice Age.
[Illustration: Gray whale breaching. _Photograph by T. J. Walker._]
[Illustration: Another gray whale "spyhopping." Notice the narrow
tapering head, typical of the California gray whale. _Courtesy of
the Scripps Institute of Oceanography._]
_Geographic Distribution_
Today the species is restricted to two distinct populations existing on
opposite sides of the Pacific. One herd summers in the Sea of Okhotsk,
migrating southward to Korea where, in the open bays, calving takes
place in January, February and March. The larger population summers off
the coast of Siberia and Kamchatka, migrating clear across the Pacific
Ocean to California and then south to the breeding lagoons near Bahia de
Sebastian Viscaino, situated on the outer coast of Baja California. A
few whales have been noted around the tip of Baja California and in the
gulf itself. These are part of a small group which calve in lagoons
along the mainland of Mexico just inside the Gulf of California. It has
been suggested that the recovery of the species was possible because
these lagoons were unknown to whalers. It is, however, unlikely that the
whalers continued to whale until they had completely wiped out the
populations of the main lagoons. The inability of the species to support
intensive whaling suggests both a limited population and an animal with
a low reproductive potential. Since 1850 there have been three brief
periods of whaling, each separated by about 20 years. Each succeeding
period of whaling has been shorter, suggesting that 20 years is not a
long enough recovery period.
_Shore Habits_
Generally speaking, shallow water is dangerous for the larger whales,
other than the gray and right whales. Strandings of the other species do
occur, which can be interpreted to mean that these whales are not afraid
of shallow water. However, when they strand they die. The cause of
stranding is difficult to determine. Perhaps the victim is sick and
drifts ashore. Most strandings occur during severe storms which quickly
obscure the bottom features by stirring up the sand and mud. The
stranding of the pilot whale is most dramatic because entire groups will
come ashore as if afraid to go back to sea. If man intercedes and helps
free them, they still refuse to escape. The cause of the panic and
subsequent action is unknown, although it is unlikely that the action is
mass suicide as so colorfully described in newspaper accounts. Most
other strandings suggest that the whale was out of its normal habitat.
The gray whale, however, has no difficulty in this dangerous region, and
in fact they negotiate the treacherous turbid channels of the lagoons,
notwithstanding the strong tidal currents which flow through them. They
have also been observed rolling in the surf in water barely deep enough
to float them. Should stranding occur, they seem to realize that it is
only momentary as another swell will come along to free them. For the
other species, stranding produces fright and struggling which only
exhaust them and lodge them deeper into the bottom. Death usually
results from overheating, although it is noted that a stranded whale
finds it difficult to breathe normally because the weight of the body
out of water crushes the chest cavity.
At the present time it is difficult to understand why the lagoons are
used by the gray whale for calving. It may be an ancestral behavior
trait which has been inherited. It is most likely, however, that the
quiet waters facilitate birth and nursing during the time the baby is
gaining strength for the long migration. The observation that the whales
may roll and rub themselves against the muddy banks has led to some
conjecture that the lagoons help control the skin parasites.
You may wonder whether the lagoons, which are limited in number and in
extent, may control the size of the population. Lagoons are subject to
change in size and depth through geologic processes, and they may be
created or destroyed. The lagoons which are used by the whales are
remote and seldom visited by man. You wonder whether the whales would
continue to use them if they were also used much by man. The California
gray whale has not used San Diego Harbor for over 100 years. Perhaps San
Diego Bay was used because the other lagoons were then overpopulated.
Certainly the total population of whales has never again reached the
numbers which existed before the whalers started.
_Scientific Description_
It has already been mentioned that the gray whale was described by
Professor Cope in 1868-69. The scientific name by which he tagged it,
_Rhachianectes glauca_, describes the fact that the whale is blue-gray
in color, and that it frequents rocky reefs. Because the species did not
resemble any other whale, he placed it in a separate family, the
Rhachianectidae. Cope was not aware that paleontologists had found and
described fossils of whales which were very similar to the gray whale.
Of course, the paleontologists working in Europe did not know that there
was a living representative of these fossil whales which they had named
_Eschrichtius_. However, this oversight was finally realized by Dutch
cetologists Van Deinse and Junge, who in 1937 corrected the mistake by
placing the gray whale in the genus Eschrichtius, discarding the old
genus name Rhachianectes. If you wish to search the scientific
literature on the gray whale prior to 1937, you must look for it under
the old name Rhachianectes. This is not the first or last time a
scientific alias will be produced; yet this one serves to dramatize the
fact that the gray whale is truly a living fossil, which is a reminder
of some of the evolutionary steps over which the other whales passed to
gain the structural and behavioral features needed to occupy the many
areas of the oceans.
[Illustration: Infra-red photograph of a gray whale. Note the
lingering spout and the blow holes at the forward end of the
surfaced whale. _Photograph by T. J. Walker._]
_Reaction to Whaling_
The California gray whale is known by other common names, such as "Koku
Kujira" of the Japanese, which means "the devil fish." This indicates
the cleverness of the gray whale and the dangers associated with hunting
it. Whalers universally considered this species the most difficult to
whale and the only one which might charge the boat. Gray whales
certainly seemed to learn quickly the dangers to them from whaling.
Captain Scammon considered this species the most interesting, giving it
top billing in his book on the _Mammals of the Pacific Coast_. He
reports that it was standard practice in the lagoons to kill the baby in
order to lure the mother into harpoon range. In these encounters, the
whalers showed great courage standing the charge of the angry mother, as
they took a chance of losing their boats and their lives. The females of
other whale species have a strong maternal instinct, but none of them
seems to be so consistently willing to fight for its young as the gray
whale.
We still do not know much about the behavior of the gray whale or the
other filtering whales. At present, the people who are best informed on
this subject are the whalers. They can ill afford to waste valuable time
trailing whales which are too wary to be approached. In general, feeding
whales are easiest to approach, being intent on feeding and completely
oblivious to the approach of a whaling vessel. At other times, the
whales are disturbed by the least noise. Ordinarily, once a whale is
harpooned, it attempts to escape its tormentors, rather than turn and
demolish the boat, which of course, would have put an early end to
whaling. In the instances where a whale has rammed a boat, it is usually
an accident, occurring during the death flurry. However, there are
exceptions, and of course, these make whaling hazardous.
_How Do They Sleep?_
One question about whale behavior that remains somewhat unanswered
is--how much rest do whales require? There have been indications that the
California gray whale in the lagoons of Lower California may rest a good
deal. However, the question of sleep during the long migration or on the
feeding grounds, has not been answered, and as yet attempts to determine
this have been hardly more than preliminary tries. In order to succeed
at this venture, observers must be able to remain close enough to the
whales at night to be within sound of the spouts. Limited visibility at
night, and the amount and direction of the boat's drift, make it
difficult to keep contact with a whale spouting only once every 4 to 15
minutes. The scientists who sail with the whalers to study whales are
too busy with the daily catch to consider this problem of how much a
whale sleeps. Occasionally, a whale is struck by a ship during the
night, and this is considered as indirect evidence that the whale was
asleep on the surface.
_Migration Groupings_
The California gray whale is not believed to be particularly gregarious.
The groupings observed at the lagoons are thought to be due to the
limited areas which are available for mating and calving. There is some
indication that they form groups during their migrations. Russian
observers say that early in autumn groups gather and start out on the
migration. The Japanese have noted groups of moderate size remaining
together during the crossing of the Bering Sea. As yet no one has
attempted to trail a group of grays along the entire migration route.
Not only would this establish the route, but might also add to our
knowledge about their behavior en route.
At San Diego three categories of migrants have been observed on the
southward migration. During the early and middle periods of the
migration, many individual whales are seen apart from the group. These
are believed to be pregnant females. They travel at about 4 knots and
surface frequently, about every 3 minutes. The migrating groups of three
to five are believed to be nonpregnant females accompanied by one or
more males. These are already courting, and it appears that the males
are jousting for the attention of the females. At any rate, the
migration is less hurried, and the individuals spend a great deal of
time on the surface, blowing and milling about. Such groups are seen
principally during the middle part of the migration, and they are
easiest to sight. They afford the spectators at Cabrillo National
Monument quite a show. Not infrequently, these groups put on a display
for an hour or two. It is difficult to observe all the details of
courtship, but it is believed that during mating the animals lie quietly
in the water. On the migration, the courting whales roll over in the
water extending the flippers alternately like spars. Mating generally
takes place near the lagoons and also in the lower ends of the lagoons.
A few matings have been observed at Point Loma.
_Breaching_
Occasionally the gray whale will burst out of the water at about a 45
degree angle, and will turn over, falling back with a tremendous splash.
This is called breaching, and its significance is not known. Although it
is considered part of the courtship behavior, this is difficult to
reconcile with the observation that it is more frequently displayed by
solitary migrants. Whales may breach more than once, and in fact, one
was observed to jump repeatedly, as many as 25 times within an hour's
passing of the Point Loma area. Here one or two migrants will breach
each week. Unfortunately, the act takes place so quickly that you only
notice the final splash, at best obtaining only a quick glimpse of the
whale's massive body. However, this sight repays many hours of patient
watching.
Toward the end of the season you see that the migrants are smaller and
closer to shore, frequently just beyond the surf. These are believed to
be last year's young, making the trip alone for the first time. They not
only swim more slowly, but they also seem to wander into the kelp and
into every irregularity of the coast. Those which enter the kelp may
raise the head vertically out of the water in an action called
spyhopping. They are obviously trying to find a passage through the
kelp. The fact that the gray whale does not spyhop regularly on its
migration along the shore must mean that its orientation is based either
on the sound of the surf or the depth of the water. Spyhopping is
apparently employed by the whales in the lagoons, and it has been
observed frequently for the other species in the ice floes of the polar
seas.