Are crocodiles immortal? The short answer is no, they’re not. Sorry for being a fun-ruiner right off the start, let me explain further:
Crocodiles aren’t immortal in the sense that they’re incapable of dying, more along the lines that they could, under the right conditions, live for a very, very long time. Crocodiles die just like everything else on this planet eventually does (excepting some jellyfish, but that’s for another day), but it’s how they die that makes them extraordinary. See, crocodiles have this thing called negligible senescence. Sound complicated? It’s not. It simply means that aging has no effect on the health of a crocodile, physically or otherwise. A seven-year-old crocodile is fundamentally in the same shape and health as a seventy-year-old crocodile. Pretty nifty, huh? That would be a nice trait to have for ourselves!
So how do they die if aging doesn’t affect them? In short, the world itself and the aspects of life that a crocodile has to deal with – eating, mating, fighting – all are factors that impact the lifespan of a crocodile. If a crocodile is hurt while hunting, then it can’t feed itself. It starves to death, simply put. If a crocodile is struck with disease or illness then it dies, just like anything else would. If it grows too big that it can’t feed itself then it will die then, too. The crocodile isn’t immortal, but it does live without being hampered by the negative side effects that come with aging. There’s been evidence of this negligible senescence in other creatures, but for the most part they’re simple creatures like lobsters and sea urchins.
So why don’t we see centuries old crocodiles running around? Well, for one, we sometimes do.
Meet Cassius. He’s one of the oldest known crocodiles currently alive, coming in at a whopping 112 years old. Minimum. Minimum, you might ask? He’s been scientifically calculated to be at least 110 years old due to his “size, growth rate, and condition”, as well as other factors. So he could be older, but he’s at least 110. He lives at a crocodile park located at the Great Barrier Reef, and is also the largest captive crocodile alive, weighing in at over a ton.
Well, that’s one example, but maybe he’s just an outlier? Another contender to the “oldest crocodile” claim is Henry, who claims to be older than Cassius by about 3 years, give or take. He’s in captivity as well, which you’ll find is a running theme. The oldest crocodiles are also the ones who live within a protected space. Food is given to them, they have vets on hand if something goes wrong physically, and they never have to battle other crocodiles for mates or territory. They live a life of ease and that, in turn, allows them to simply keep on living. When they do eventually die it is often because of stress, a common ailment amongst wild creatures that are kept captive.
So maybe now you’re asking, “so what”? Well, as with all things having to do with nature and immortality, humans are interested in learning if it could ever benefit them. And the answer is yes, it could. Right now British biogerontologist (study of aging and how to slow it) Aubrey de Grey is working on Strategies for Engineered Negligible Senescence (SENS), or, in this case, he is attempting to figure out how to make humans similar to crocodiles. In the future we, too, could live without feeling the negative effects of aging. Of course this a long way off, but it never hurts to dream, right? I mean, I’m still waiting on my flying car!