"You're in pretty good shape, for the shape that you're in!"
- Theodor Geisel (Dr. Seuss), You're Only Old Once
It would probably be fair to say that most of the animals that I work with are a bit past their prime. For every rowdy, rambunctious youngster I take care of, I generally have two or three crotchety old cranks, slow in movement and quick in temper. They don’t walk with the same poise and grace that they did in their younger day, they don’t see or hear as well as they used to, and they tend to be set in their ways.
They’re old. Not death’s-door old (at least not yet), but definitely senior citizens. Some of our visitors see them, maybe walking stiffly or awkwardly trying to eat with teeth that aren’t as sharp and strong as they used to be, and feel bad for them. I generally don’t. Old age… that we could all be so lucky.
One of the questions that I get the most often – I enjoy the least – is “how old can [the animal] live to be?” It’s a tricky question. Consider - how long can people live to be? Most of us would say into their 70s or 80s, some of us know folks in their 90s. Some exceptional invididuals live to be past 110 years old.
Does that mean that people live to be 110?
There is a difference, which needs to be explored, between two concepts
Longevity – How long an animal CAN live to be. In the case of humans, maximum longevity is over 110 years old, though few of us will reach this milestone
Life Expectancy – How long an animal is EXPECTED to live to be. Again in the case of humans, life expectancy (varying by country) is about 60-70 years. The important thing to remember about life expectancy is that not everyone reaches it – if they did, it wouldn’t be an average. Half will live past that, half will die before that.
What does this mean for zoos? For one thing, we should be publicizing life expectancy rather than longevity. Yes, we’re all very proud when an animal lives well past its usual life expectancy; we feel that it shows good care on our part. That being said, if we boast that an animal can live to be 50 years old, and the one at our zoo dies at age 40, it sets us up for complaints and criticisms (“Oh, he died young! Something must be wrong with the zoo!”), when 40 might actually be a much more reasonable lifespan for that species (it would be like your grandparent passing away at age 85 – is that “dying young?”). Animal Rights Activists play this card all the time, especially with elephants – using the occasional, exceptional long-lived elephant to make the other elephants seem to be dying too early.
That being said, I’m sure all elephant keepers would say that all elephants die too young… including the oldest ones.
If there is one area in which there is heartening news, it is that zoo animal life expectancies have continued to increase over the years. When William T. Hornaday wrote the guide to the New York Zoological Park (Bronx Zoo), he advised the readers that, if the zoo were lucky enough to display a gorilla, they should hurry and see it immediately, because it would probably die before too long – the legacy of improper feeding, improper housing, and improper care.
Today, zoo animals live as long – usually longer – than their wild counterparts. The care of geriatric animals is one of the most dynamic aspects of zoo medicine, as animals continue to live longer and face more age-related health problems (sometimes it feels like I feed out more pills than food to some of my older animals). Animals in the wild do not die of old age. The stiffness in the walk, the blurring of vision, the other symptoms of old age that spell death in the wild are nurtured in a zoo setting.
As I walk around the zoo and see our older animals (especially my favorite old wolf, nicknamed “the Grey Lady”), I am sometimes saddened that they no longer have the energy and vigor of their youth; it’s especially plain when you see them with younger animals of the same species, sharing an exhibit. That being said, I take satisfaction in the fact that we provide them with comfortable homes to live out their golden years. As they get older and the expectations of exhibit and breeding potential pass them by, we become free to spoil them with their favorite treats, make them comfortable beds, and let them be the cranky, crotchety old beasts that the keepers all know and love.