Aside from man, who will not be considered in this discussion, the elephant has the reputation of being the longest-lived mammal. One frequently sees statements credited even by some biologists that it lives for 150 to 200 years.
The question has been investigated recently by several biologists, who have found that there is no positive record of an elephant’s having lived to be one hundred years old. It has been reasonably well-verified that one elephant attained an age of over sixty years, and several over fifty years of age are known. Another elephant is said to have lived in the United States for eighty-five years, but I have not been able to confirm this report.
It seems probable that elephants do live about as long as any other mammal and many authorities believe that an occasional specimen may reach one hundred years.
Comparatively little information on the maximum age of whales is yet available, but most biologists are of the opinion that they do not live so long as many other mammals. Whales have been killed whose bodies contained harpoons that were marked with the date when they were made. From this “harpoon evidence,” one whale is thought to have been approximately thirty-seven years old at the time of its death.
The domestic horse probably lives as long as any other mammal with the possible exception of the elephant. Ages of from fifty-four to sixty-two years have been reported and biologists who have investigated these claims have provisionally accepted ages of over fifty years as approximately correct.
Known ages for other mammals kept in captivity include a hippopotamus of forty-one years, a rhinoceros of forty, several kinds of bears of thirty to thirty-four, a chimpanzee of twenty-six, and monkeys of over twenty years.
Domestic cats and dogs have done well. Cats of twenty-one and twenty-three have been reasonably well verified, and others of twenty-seven, twenty-nine and thirty-one have been reported. Dogs of eighteen and twenty-two years are provisionally accepted, and one is reputed to have lived for thirty-four years.
One of the most amazing records for mammalian age has been established by a spiny anteater, one of the two types of mammals that lay eggs. This little animal, appropriately named “Prickley Pete,” has lived and thrived in the Philadelphia Zoo for more than forty-two years and, at last report, was as lively and healthy as ever.