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.