What would be a plausible reason for a prey animal to mimic its own predator?

Question

The saying goes "a wolf in sheep's clothing", which is a biblical idiom to refer to someone pretending to be harmless. This got me thinking about if the reverse could also be true. So I came up with a fantasy creature, which is a sheep in wolf's clothing in a very literal sense.

The wolf sheep or "Weep" as I like to call it is identical to its real life counterpart, except for the layer of wool around its body which can take the form of a wolf. The Weeps mimicry is so detailed that it can impersonate a wolf to perfection, even going as far as to imitate the howling and other behavior. A shepherd that didn't know of the creature beforehand wouldn't be able to tell it apart from a real wolf or from an ordinary sheep.

What I can't wrap my head around is why this creature would need to mimic its own predator?

Answer 1

I think the more important question is: "Would any plausible reason outweigh the benefits?"

The weep's anti-predation tactic comes with a massive helping of selective unfitness that you don't see in real world examples of gilbertian mimicry. If they themselves cannot tell the difference between a wolf and a weep 95% of the time, then that 5% they do figure it out is going to be when they get really close and personal... like when trying to mate. If a wolf actually eats weeps, then mating becomes a game of russian roulette for the weeps. In general, risking death in mating rituals is only selectively fit when the risk can guarantee procreation regardless of survival (as you see in many spider species).

The best solution to this would be that wolves are predators, but they do not eat weeps. Much like the batesian mimicry that happens between venomous and nonvenomous snakes, the weep picks an animal that does not want to eat it but is dangerous to its predators. This way other animals who absolutely have no reason to get close to a wolf will rarely get close enough to the weep to tell the difference, but weeps are not risking their lives getting close enough to wolves to see if they are viable mates.

To explain this, I would say that the weeps started off with an evolutionary trait that made them very nasty tasting or toxic to wolves, but not similar predators. The wolves stopped eating weeps and focused on other game animals in the area. However, another predator like jaguars or something don't mind the taste and kept on eating them. The weeps begin flocking near wolf packs for safety because the jaguars prefer to avoid confrontation with wolves, but the weeps would still get picked off if they wondered too far from the wolf pack. Over time the weeps begin to look and act more like the wolves making Jagours more and more nervous about hunting them. Eventually, the weeps look enough like wolves that they no longer need to stay near wolf packs for predators to avoid them based on looks alone.

Answer 2

This is known as "Batesian mimicry"; a harmless mimic species adapts the appearance of a "model" species that other animals including predators of the first species don't want to mess with. A rare specialization of this is Gilbertian mimicry, where a species adopts an appearance specifically related to its own predator to discourage predation.

Most Batesian examples are mimics of aposematism (warning coloration); a harmless species adapts the bright coloration that their model has developed to discourage attacks, without also adapting the feature that the model species is warning about. Predators learn that the model species stings painfully, makes them sick or just tastes really bad, and so they avoid not only the model species, but the mimic as well, not knowing (or at least not willing to take the risk) that the mimic species really is harmless (and tasty).

There are a few species that don't mimic warning coloration, but instead mimic a more "typical" coloration of a predatory species. The "brainfever bird", a species of cuckoo in India so named for its distinctive call, has adapted an adult appearance very similar to a species of goshawk called the shikra. You don't typically mess with a bird of prey, even if you're a larger bird, so the brainfever bird goes largely unaccosted by all but the largest birds of prey in the subcontinent. Similarly, the hognose snakes, especially the North American Heterodon genus, have adapted both an appearance and behavior similar to various species of rattlesnake, with the similar goal of avoiding trouble from various snake-eating predators that would really rather not have to deal with a rattlesnake bite today.

Gilbertian mimicry is rare, and involves a species specifically adapting a feature of a predatory species that discourages predation. The Wikipedia example is a species of passion flower that a species of butterfly has come to specialize in eating in their larval stage. To discourage that, the flower evolved the appearance of the butterfly's eggs already laid on the plant, discouraging butterflies from laying their own eggs for fear their young will get outcompeted by the more mature eggs.

Batesian and in fact most types of defensive mimicry work best when the mimic species is heavily outnumbered by the model species; it's less likely a predator will learn to see animals with that appearance as food, if most of the examples the predator is likely to encounter will ruin the predator's day. If the mimic outnumbers the model, the predator's more likely to happen on the mimic species the first few times, figure out they are tasty, and at least risk approaching any similar animal, learning to differentiate by other behaviors whether what they are about to eat is the mimic or model.

That is going to be the biggest problem with the widespread adoption of mimicry by sheep species as we know them. Sheep are very numerous, having adapted their own survival strategy via a strong herd mentality and mass reproduction, out-breeding predation to maintain their numbers. This is very typical prey species evolution; the predators can eat as many individuals as they can catch, the prey will still endure as a species by making more babies than the predators can eat. While Gilbertian mimicry predicts a mimic tactic in a more numerous species, its most common examples are in plant/insect interactions; animals can very rarely successfully pass for their own predator (some fish school in large groups to look like a bigger fish; that's about the only example I'm aware of and some predators play it to their advantage). The upshot is that sheep that look like wolves are going to heavily outnumber actual wolves, and with the sheep herding instincts versus the pack's looser hunting skirmish line, it's pretty easy even at animal intelligence levels for the wolf to recognize their prey animal.

The more successful strategy, at least for domestic sheep, has been for humans to breed domestic dogs to look like sheep. These sheepdog breeds, including the Great Pyrenees, Komondore, Kuvasz and others, are bred for large size, light-colored long coat, a friendly demeanor that differentiates them from more authoritative herding dogs, and good protective instincts. This allows these sheepdogs to blend into the herd until a threat like a wolf nears, at which time the domestic dogs put themselves between the wolves and the herd, at least stymieing the wolves' efforts long enough for the shepherd to close distance with their own weapons. This form of human-engineered mimicry doesn't have a name as such, as it's not the result of a true evolutionary pressure but of intentional selective breeding (and no wild animal is known to have evolved as a mimic of a model for the model's advantage; some predatory mimicry involves mimicking a model specifically to lure that model's predator as prey, but the model species rarely sees any practical benefit).

Answer 3

For subverting mating competitions.

Imagine that the males are all over here, butting heads or displaying their tail feathers, or whatever, trying to attract the admiring females.

Right now, I'm imagining something like a cross between a peacock and a mountain goat.

Now here comes Fred. Fred does not quite have as good horns, nor as attractive tail feathers. But what he does have is a really convincing ability to mimic a hyper-wolf. So he "pulls" this face at exactly the right moment, possibly with a little bit of the old "Step and growl." And all the competing males suddenly decide they left the creek running back home, and take off.

Leaving Fred unopposed on the mating competition field. "Hello ladies!" And Fred therefore leaves a lot of children who inherit his ability.

Answer 4

They don't mix but mimic a pack

The main challenge for your Weep is that wolves are social animals and so much more attentive to the identity and behavior of other wolves around them than solitary predators would be. Roaming undetected in a pack of wolves would be impossible as even real wolves unknown to the pack are challenged on sight, fought and possibly killed.

What they might instead do is mimic an entire pack with their herd, marking their territory with fake wolf-smell and roaming around, chasing other potential prey in mock hunts.

This way they clear the area of other herbivores, increasing their own food supply. Also, Weep outbreed wolves, so a fake pack is typically larger than real packs, discouraging all but the most desperate real wolf packs from confrontation.

Of course, if the real wolves do engage in a confrontation, the game is up and the Weep will lose a fair number from their "pack" before the rest escape and go looking for new territory.

Answer 5

Though I can't figure out how learned scientists could ever proved such a thing, it is believed that butterfly wings have evolved to look like faces as an attempt to scare potential predators.

Your weep is just a more extreme expression of this survival technique. Looking like a wolf might not scare away other wolves, but it would definitely discourage all the lesser predators which might otherwise attack a defenseless sheep.

Answer 6

Ultimately, this kind of mimicry is a survival strategy. The sheep that can mimic a wolf gets to make more baby sheep, on average, than her fellow sheep who have already been eaten by wolves.

What you're describing is a kind of mimicry, similar to Batesian, which is where a prey animal mimics some kind of noxious animal that the predator avoids. Observing the same signal in the mimic prey, the predator will avoid. And also Vavilovian, which is where one species comes to look or behave like another due to selection pressure.

Your sheep experienced some mutations in wool colour and behaviour that allowed them to pass more or less unnoticed by wolves. Your shepherds consciously or unconsciously selected for this mutation to the point where the modern sheep howl and look something like wolves.

Answer 7

One example of this from the real world: moths that mimick jumping spiders, so that jumping spiders start protecting their territory rather than eating them.

This is a form of Batesian Mimicry

Answer 8

Perhaps there are very few large animal species around, the environment is fairly open and the prey animals are solitary. It might then be possible for the prey animal to mimic its predator.

If all the animals were solitary the weep would simply avoid any other animal it saw in the distance, weep or wolf whereas the wolf equivalent would find it was often chasing another wolf. There could even be an interesting behavioural game of chicken. If the wolf learnt only to chase those animals that ran away, the weep might evolve to initially start chasing the wolf in order to prove that it was also a wolf and make the real wolf give up and so on.

That said the situation is fairly unlikely as there are probably too may clues that would give the game away other than camouflage such as smell and even more difficult to mimic grass chewing teeth and eating vast quantities of grass all day.

Answer 9

Lots of good answers here but I don't see the idea that occurs to me why a sheep would take on the appearance of its predator like a wolf. Simply put it had less to do with the predator itself, and more to do with other sheep running from wolves.

All of a sudden this alternative species of sheep is able to take whatever food and territory it wants from its main rival/competition, all at the cost of some appearance altered and threat displays.