The RoVing Naturalist
By Dennis Prichard
How old do animals get? That is a good question – one that’s not easily answered. Different methods are used to tell each animal’s age, and then these methods don’t always hold true. Of course those animals living in zoos have exact ages known, but these are not truly natural life spans, being free from predators, diseases and famines. Still, they give us a maximum age an animal might attain if conditions are just right.
A few axioms might apply to mammals’ lifespans. One is that the larger the mammal, the longer it lives. Of course a grizzly bear lives longer than a shrew, but bats can live to 30 years while similar-sized mice only last four. Due to the bat’s behavior of hibernating, the lowered metabolism causes it to conserve energy and, more importantly, time. Its cells and tissues do not wear out as fast as the mouse. Also, Shetland ponies will usually outlive a regular-sized horse.
Mammals’ teeth can sometimes show how old they are by the annual rings in them, or the amount of wear they have. These two methods have their benefits but can also be faulty, especially in areas where sand or other abrasives are present, wearing down the dentition faster than normal.
Birds have been aged accurately in the wild by the use of leg bands. Scientists and wildlife professionals attach metal bands to birds’ legs recording the age when caught, date, place and other vital information. Records kept on banded Caspian terns revealed one to live 26 years in the wild, while California condors may reach 69, and swans go more than 70!
Reptiles, again because of their lifestyle of dormancy, tend to be champions of longevity. A rattlesnake was recorded at 18.5 years, while boa constrictors surpass 20 regularly. Tortoises get the prize for living past 170 years. If you have pet box turtles, you might want to make plans to pass them on to one of your caring heirs as they have been known to live 123 years.
You would think insects would rank among the lowest in lifespan contests. Most only live one season. Some live a full year or two as larvae, like the mayfly, then last only 18 hours as an adult. But queen ants can live 15 to 20 years, and a queen termite surpasses that easily at 50. Capable of laying thousands of eggs each day, the queen keeps her colony thriving and the pest control industry in business.
Mind you, these are world records, most of which were pampered along by zoo attendants and veterinarians. With this care lacking in the wild, animals face their demise much sooner from starvation, predators, diseases or the elements – nature’s methods of population control.
Dennis Prichard is a retired park ranger. He’s worked and studied wildlife at many National Parks and Wildlife Refuges including Carlsbad Caverns, Mammoth Caves, the Everglades, Sequoyah NWR in Oklahoma, Sevilleta NWR in New Mexico, and Isle Royale National Park, to name a few. He travels in a fifth wheel with his wife and dog, a Labrador named Cricket.