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| Description: Why do tortoises live so long? 1. Slow reptilian metabolism. They burn energy slowly. In one study, an adult Redfoot tortoise was found to only use about as much energy provided by half a banana over a several month period. 2. Vegetarian diet. They don't have to hunt, stalk, trap, or wrestle their food which all takes a lot of energy. Vegetation digests more slowly and takes energy to digest. 3. Lack of predators. Once a tortoise hits a certain size, little in the area can prey on it. At that point, illness, injury, and starvation become the main threats. Note that the oldest known species are those which are either big, or live in places with little predation, or both. The record breakers are also in zoos. 4. Sedentaty lifestyle. Besides foraging, tortoises don't move a lot most of the time. Even foraging rarely takes them outside a rather small territory. 5. Stress resistance. I am not sure exactly how to classify this, but tortoises don't seem to get stressed over stuff. They rarely react to noise or vibration. They deal with challenges in a very phlegmatic manner. They rarely seem to get too worked up over things other than potential rivals or mates, or food. Call it the 'twitchiness factor'- mice and other short-lived vegetarians are notorious for their twitchiness- always on the lookout, responding to EVERY little noise or motion. If mice are a 10 on the Twitchiness Scale, tortoises would barely rate a 1. 6. Good PR. This may be the best point. The oldest decently documented tortoises are only around 175, and even these guys may be frauds since the records get sketchy throughout their lives. The best documented lifespans are around 125-140 range for a lucky few and most tortoises are lucky to break the 100 years mark. However, you will see claims for 200 or more years for these guys- possible, but unverified! Picture Stats: Views: 1295 Filesize: 88.06kB Height: 387 Width: 628 Source: https://biology-forums.com/index.php?action=gallery;sa=view;id=14332 Keywords: Blog |