The Social Behavior of Older Animals

4 Leaders

chapter 4 Leaders C hapter 3 discussed how older elephants make superb leaders, in large part because of their age and experience. Various whale leaders are undoubtedly as experienced and wise as elephant matriarchs, but we must infer this, because we are not able to see much of what they do in the dark waters where they live. This chapter valorizes older and experienced female orcas and sperm whales, two large and long-lived cetaceans about whom more is known than most aquatic mammals. Elderly females of these two species, like older female elephants , are born into intensely social groups so all-encompassing that the members will never be on their own until the day they die. However, orca males and females live together; in sperm whales, they lead largely separate lives. The less-studied baleen right whale is also considered, because aged individuals seem, by inference, to be leaders, although this has not been verified. The leadership or past leadership of some alpha animals will be mentioned in future chapters, but this chapter ends with varied information on leaders of terrestrial species: sheep, goats, mountain goats, red deer, elk, baboons, and langurs. Aquatic Leaders orcas Tourists leaning over the rails of ferries crisscrossing the coastal waters of southwest British Columbia are thrilled to see a pod of orcas (Orcinus orca) sail past. (I refer to this species as “orca” rather than “killer whale”; the word “killer” has a negative connotation which could, in reality, be applied to all predator species, including human beings.) Not that the ferry passengers usually see much—only dorsal fins cutting through the waves: those of the large males a rigid 1.5 m (5 ft), those of the smaller adult females 0.6 m (2 ft) shorter. If there were a whale researcher on 38 board, he or she could tell the passengers that all the hundreds of orcas living in the area are known individually to scientists, each recognizable by characteristics such as the shape of the dorsal fin, nicks or scratches on this fin, and saddle markings (Hoyt 1990). Scientists may know which orcas swim about together, but otherwise their work is largely done while these researchers are blindfolded, in effect , except for the occasional glimpse of a fin or a fluke. Nor can they decipher what the orcas are saying to each other by listening to their complicated whistles, squawks, squeals, and clicks through hydrophones, although scientists now often know who the vocalist is by his or her signature call. To calculate the approximate age of an orca female in the Johnstone Strait area of British Columbia, researchers counted the number of young who accompanied her on her ceaseless roaming through its many passageways . A female orca becomes sexually mature at the age of 12, a gestation period is 16 months, her first young is usually lost, and she nurses each newborn for several years before pregnancy and the birth of her next offspring (Morton 2002). A female can live to be 60 or more in the wild if she is not killed by human beings, her only predator. However, one expert described a captured female orca as “old” even though she was only in her thirties, and even at age 25 an orca’s teeth can be extremely worn (Hoyt 1990). Males are much more difficult to age. At 20, their enormous dorsal fins are fully grown, so at least a minimum age can be estimated if there are photos taken in earlier years of individuals with adult fins. Perhaps in part because these protuberances cause a terrific drag for the males as they swim and dive, using up much energy, they die far sooner than the females , with a lifespan of only about 40 years (Morton 2002). The much-studied orcas resident in British Columbia and Washington State waters live in matriarchies, the members staying together during the lifetime of their elderly leader, with neither males nor females transferring to other pods. The lifelong bond of a mother and her offspring form the basis of whale social organization. Adults of pods meet those of other pods now and then, so there is no problem of inbreeding. However, socalled transient orcas, which have a wider distribution and who feed largely on seals and porpoises rather than fish, do not have such a stable system. Because their source of food is more irregular, the young leave Leaders 39 [3.133.147.252] Project MUSE (2024-04-25 16...