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.