Figures for both species of pilot whales are unknown, and even though they are depleted in some areas, pilot whales are not considered to be endangered. There are likely to be almost a million long-finned pilot whales and at least 200,000 short-finned pilot whales worldwide. Humans have taken advantage of the social nature of pilot whales. "Drive fisheries," where groups are herded to the beach for slaughter, have taken place on Cape Cod, Newfoundland, the Faroe, Shetland, and Orkney Islands, Iceland, and Norway. The whales have been killed for meat, bone, fertilizer, and oil. In some places, such as the Faroe Islands, the kill continues today despite an obvious decrease in whale numbers. One drive fishery in Newfoundland killed over 50,000 whales between 1951 and 1961, rapidly decreasing the number of pilot whales in Newfoundland waters. Other kills have not had such a drastic effect. Pilot whales are also being used by man as exhibition animals. They are displayed in many aquariums and zoos.