These photos suggest two monstrous animals battling, and then a snake that might just regret its meal later. Is this a rare moment that someone happened to capture or just a standard day in the wild?
First, these animals aren't giants. That snake is likely about 15 or 20 pounds [7 to 9 kilograms], and the croc might be 5 to 7 pounds [2 to 3 kilograms], probably three feet [one meter] long. And for these species, native to that part of Australia, this is a very natural event. While that looks like a really big meal, it's a pretty common one for that type of snake. Olive snakes are known for being phenomenally powerful, pound for pound, and for feeding on large food items.
What danger is there to the snake in this scenario?
Teeth. The croc's teeth could razor right through that snake. If the croc could then shake its head, it could do real damage—but it probably wouldn't have that chance here. That's one reason snakes intentionally go for the neck and shoulder region when they attack, to try to avoid being bitten themselves. They'll grab on just behind the skull and coil up to hold the croc in place. But even if a snake is bitten, it has a phenomenal immune system and can fight off many infections. We see huge scars on wild snakes; they do get beaten up by their prey.
How does a constrictor like a python know when it's "safe" to let go and eat?
Snakes are very sensitive to their prey's heartbeat. Normally a python will constrict until the animal asphyxiates and the heart stops. But crocs can go a long time without oxygen. In this case I'd guess that the snake constricted with such force that it compressed the chest cavity until the croc's heart had no room to beat. So the croc probably died of cardiac arrest rather than suffocation.
We always hear that snakes can "unhinge" or dislocate their jaws to eat big food. Is that what's going on?
No. Snakes have no chin, no chin bone, so their jaws aren't connected the way ours are. There's nothing to dislocate. Instead there are really stretchy ligaments that determine how wide the mouth can open.
Snakes seem to "know" to eat their prey from the narrowest point—the mouth end—which makes the animal easiest to swallow; is this instinctive?
There's probably some instinct at work there. It's a particular behavior you see with snakes in the wild and captivity. After killing the animal they'll let go and rest. Then before eating they'll search around using their nostrils and tongue to find the smell of saliva from the animal. That's the end they want. With crocs there isn't saliva per se, but maybe the smell of mucus does the trick.
What's the biggest prey item you've heard of one eating?
It was a scrub python—closely related to olives—that ate a wallaby that was about 110 percent of its body weight. That was a good-size meal. But snakes regularly eat items 75 to 100 percent their size.
What do you make of the case in Florida in which a Burmese python's body burst after eating a crocodile? Did the snake use bad judgment about how much it could handle?
Snakes may occasionally start eating something and then abandon it after realizing it's too big. But that's not usual. Here's what actually happened in Florida. The snake successfully killed and ate the croc, swallowed the whole thing. The snake did win. But Florida is an unnatural environment for that snake species; it's not as warm as the snake's habitat in Southeast Asia. So the snake couldn't digest fast enough to keep the food from rotting. Once it started to rot inside the snake, the snake began to die. Its body split open because of that process, not because the croc was too large.
Back to Australia, after eating the Johnson's croc, how long might that olive python go without eating?
These are ambush predators, so the snake isn't likely to pass up another meal that came along. It would go relatively dormant for about ten days to digest, but over the next three weeks it would take what it could get. However, the caloric needs of that type of snake is pretty low. It could certainly go the rest of the season without a meal.
What parts of the croc can the snake use for energy?
All the bones, flesh, and organs are digested and used. A lot of scales will pass through, and the teeth, over the two to three weeks after the kill. Things with keratin and enamel aren't digestible, so they'll come back out.
Source: NG
頂級掠食者是如此強勁! |
發表於 2014-3-5 08:36 AM
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