捕食关系中的模仿行为_Mimicry in Predator-Prey Relationships

[00:00.00]Narrator: Listen to part of a lecture in a biology class.
[00:06.77]Professor: We’ve been discussing predator-prey relationships. [00:10.66]Will someone summarize what we went over last class?
[00:14.35]Male: We focused on camouflaging where a species tries to blend it with its surroundings in order to hide from predators. [00:22.90]You gave us examples like the octopus. [00:25.82]Octopuses can change the color and even the texture of their skin to blend in really well with their environment.
[00:34.01]Professor: Okay, and today I will type of adaption: mimicry. [00:38.69]Nothing fancy about the term here, mimicry—no mimic. Just means to imitate. [00:45.82]In biology, a group of organisms, called mimics, can develop a trait of behavior that imitates the appearance, the behavior, sound or scent of another species. [00:58.58]Unlike with camouflage, the goal of mimicry is not to blend into its surrounding, the goal is to be mistaken as some other species. [01:09.29]Again, we’re talking about this in the context of predator-prey relationships. [01:15.19]Mimicry is usually used as a way for animals to avoid predation by disguising themselves as another species that looks unappealing or even dangerous. [01:28.01]When something harmless imitates something dangerous, that’s Batesian mimicry. [01:34.58]A basic example of Batesian mimicry: some flies have evolved to mimic the black and yellow stripes of bees to make themselves look more dangerous. [01:46.15]Predators associate attacking bees with getting stung so they avoid bees. [01:52.20]Flies mimicking bees want predators to think they can sting, but there are more complex cases.
[01:59.74]We recently discovered a type of octopus off the coast of Indonesia that mimics not just one animal, but several. [02:09.19]It’s the first and the only known species that can do this. [02:13.70]Researchers found it impersonating two specific types of poisonous fish and one type of poisonous sea snake. [02:22.63]It shifts its body shape and its movements to resemble these toxic animals and when mimicking the sea snake which has yellow and black bands, the octopus also changes color to have these colored bands. [02:38.81]This evidence that it may decide which animal to mimic based on which predator is nearby.
[02:45.96]Female: It’s actually a reason to turn itself into… I mean, choosing to look like a particular foreign in response to a particular threat?
[02:56.90]Professor: Exactly, for instance, when there’s the threat of being attacked by a nearby damselfish, this octopus specifically chooses to mimic the sea snake, because the sea snake eats damselfish. [03:12.26]Anyway, it’s a dramatic finding. [03:15.10]The fact that it can take on multiple disguises suggests other species might have this capability too.
[03:23.59]Okay, so much for Batesian mimicry. [03:27.14]Now, some animals use mimicry for a different purpose. [03:31.75]Researchers have been studying the margay, a small cat that lives in the Amazon jungle. [03:38.57]One time, they noticed the margay mimicking the cry of baby tamarins, a type of monkey. [03:45.77]Vocal mimicry itself isn’t unusual. [03:49.61]But, it’s usually used to scare a predator’s species away. [03:53.93]What’s odd is that in this case, the relationship is reversed. [03:59.06]Margays prey on tamarins, so they don’t need to hide themselves or make themselves seem more dangerous. [04:07.07]This margay instead tried to sound scared or threatened, to draw tamarins in close by sounding like a baby tamarin that’s being attacked. [04:18.50]So it seems that rather than using mimicry to avoid the predator, margays are actually using it to attract their prey, to find their next meal. [04:29.35]The researchers noted that the margays’ high-pitched squeals weren’t a very good imitation of a baby tamarin, but that the squealing sound attracted the attention of adult tamarins away. [04:43.85]Still, none of the tamarins really sealed the trick. [04:48.74]When tamarins got closer to the crying sound, they realized it was coming from the margay and escaped before they could be attacked.
[04:58.97]Even so, that margays even use this technique suggests that they’ve had some success with it in the past. [05:07.94]Maybe we were just observing them on an off day. [05:12.12]And margays probably aren’t the only cat species in the Amazon adopting sneaky strategies. [05:20.18]People who live in the Amazon have said that they’ve heard other cat species like tigers or cougars tricking their prey this way. [05:30.74]But those are just anecdotal reports and they still have to be confirmed by researchers. [05:37.80]This type of mimicry may not be an innate, inborn trait. [05:43.66]Margay moms may teach it to their young, so it’s possible that not all margays have this capability. [05:51.43]It might just be a learned behavior kept within families.