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Some terrestrial predators "stalk" their prey: they sneak up on it slowly, maintaining a low profile, while keeping as close to silent as possible. This makes sense from an evolutionary perspective: silent predators catch more prey.

However, the prey near where I live are hopelessly noisy. Deer will freeze if they suspect the presence of a predator, then bolt when they see one for sure. Squirrels and other small mammals run around at top speed all the time - you can hear them dozens of feet away, rustling the dead leaves around. Hedgehogs just wander, making a similar noise. It seems like the only "stealth" option they have, as far as sound is concerned, is to remain still.

Are there any examples of terrestrial herbivores evolving to move more quietly in order to avoid predation? I'm not looking for a comprehensive list, but rather simply individual examples.

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closed as primarily opinion-based by anongoodnurse, rg255, AliceD, kmm, James Jun 23 '16 at 7:43

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

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    $\begingroup$ Whoops, botched the meaning of that word. Was going for "non-human". Will fix title. $\endgroup$ – John Walthour Jun 22 '16 at 13:19
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    $\begingroup$ Could the voters-to-close elaborate a bit? It doesn't sound to me like all possible answers to this would have to be opinion-based. $\endgroup$ – arboviral Jun 23 '16 at 9:15
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    $\begingroup$ @James I can certainly see a stronger case for 'too broad' (although as with any question containing the phrase "are there any examples of" you only need one example to be able to answer "yes"). I'm less convinced by 'opinion-based', which is the reason showing at the moment. $\endgroup$ – arboviral Jun 23 '16 at 11:18
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    $\begingroup$ @James I agree with arboviral that 'opinion-based' is unconvincing. And that it takes only one example to answer the question. The question would be too broad if it were asking for all possible strategies to remain unheard, which is the direction the answers have taken it. (freezing, stealth etc.). However the question specifically asks for examples of MOVING animals that try to be quiet. These are relatively rare (sharp observation from OP!), and I think there must an evolutionary reason for this. Pity that this interesting question is closed. $\endgroup$ – RHA Jun 23 '16 at 11:42
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    $\begingroup$ I've edited the question specifying that only a single exception would answer the question. It is no longer opinion based, and no longer broad. I've initiated a reopen vote. $\endgroup$ – James Mar 27 '17 at 4:47
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Does soundproofing count?

Most predators locate prey using visual or olfactory cues; the only predators I can think of that use auditory cues are nocturnal ones - owls and bats. Bats, of course, use echolocation, so even completely silent prey are still detectable. It has been suggested that the soft, fur-like body coverings of some owlet moths (Noctuidae) and tiger moths (within the Arctiinae) help hide them from echolocating predators by passively absorbing sound, although subsequent studies have suggested that they may instead be mimicking the acoustic signature of unpalatable prey.

Garden tiger moth (public domain image: source)

I have a suspicion this isn't what you meant by 'land-dwelling herbivore', but insects are people too...

Edit: just discovered this paper from May that provides evidence supporting the hypothesis that the twisted tails of luna moths (Actias luna) disrupt tracking by echolocating bats.

Actias luna Image owned by Shawn Hanrahan, licensed under CC BY-SA 2.5

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  • $\begingroup$ Lucky for you, the question is not about vertebrates. Great answer! ;) $\endgroup$ – AlexDeLarge Jun 22 '16 at 14:05
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I think that there are too many examples of animals being deliberately quiet when grazing to count. I'll discuss specifically the exceptions you raise and how they are exceptional. Hopefully you'll see my point: A lot of grazers are quiet and cautious or failing that have other adaptive strategies for not being eaten.

Deer are incredibly quiet and cautious when grazing, and fast and agile once they decide it's not safe. Squirrels use trees as an defense - not many predators of theirs can even climb trees let alone keep up with a squirrel darting through them, (related question about bushy tails of squirrels being counter intuitive). And hedgehogs... well... how do you eat one without getting a mouthful of pain? On a bigger scale, here is a related video of a juvenile lion trying to attack a porcupine. Being unsubtle helps them.

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  • $\begingroup$ Why do you close a question that you give an answer to. If a question is answerable, it shouldn't be closed... $\endgroup$ – RHA Jun 23 '16 at 9:57
  • $\begingroup$ @RHA I agree. I got the end of this answer, realized my answer doesn't and can't really answer the question fully. Why? The question requires a massively broad answer. Do note I don't think that this question is necessarily opinion based, it's just too broad.Feel free to down vote. I'm considering deleting it if the question remains available. $\endgroup$ – James Jun 23 '16 at 10:11
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    $\begingroup$ To be honest, I was just looking for one counter-example. It seems like you've provided one - deer while grazing. Thus, a comprehensive survey of animals is not necessary, merely a single example. $\endgroup$ – John Walthour Jun 23 '16 at 12:46

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