Whales cry in pain just like any other animal and whales in the vicinity hear that. Grays in particular are very protective of their young. That's why commercial whalers knew that if they got into breeding grounds and harpooned a calf they could get mum, too, because she would come running. Under attack, they were anything but docile. They reacted strongly and violently.
Gray whale leaps up for a look around, an activity known as breaching.
Ford rules out a quick regression to such behaviour but warns that repeated pursuits could change grays' relationship with humans. He points out that while professional whale watchers police themselves, recreational boaters are not always so willing. Dr. Paul Spong, who studies orcas from Hanson Island in the waters between Vancouver Island and mainland British Columbia, says that since commercial whaling ended, a new generation of grays, particularly residential grays, learned friendly behaviour by the way they have been treated by people. Gray whale blows out air while surfacing to breathe near Sea Lion Caves at Cape Blance, the westernmost point of the U.S. mainland. Migration patterns could also be affected.