California Gray Whale
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.
Gray whale breaching. Photograph by T. J. Walker.
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.
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.