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Friday 6 September 2013

5 DECEPTIVE, TWO-FACED SPECIES


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Masters of Deception: 5 Two-Faced Species
By Liz Langley,
National Geographic, 5 September 2013.

When we call a person two-faced, it’s an insult. But for some clever animals, being two-faced is a high compliment.

Many animals evolve eyespots and even false heads - like the thorny devil - to look more menacing and fake out potential predators.

But a 2010 study showed that the deceptive body parts don’t really have to look like anything - just be larger than life to produce the desired effect (seems to work for Lady Gaga). Here’s a roundup of five amazing “faces” that aren’t actually faces at all.

1. Peanut-Head Bug

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A peanut-head bug in Costa Rica.

Class act Mr. Peanut might feel it’s a bit déclassé to have his mug compared to a bug, but there’s no getting around it: The peanut-head bug has a head that looks like an unshelled peanut, and it is the coolest thing since sunglasses. Crazy cool.

Fulgora laternaria also goes by the names lantern fly and alligator bug, and one look at its faux crocodile smile and you can see why. Even with a “face” like that, it doesn’t bite, instead sucking up nutrients from plants through straw-like mouthparts.

An insect with no bite would really need other defenses - after all, who doesn’t like to snack on peanuts? In addition to its tricky reptilian head, the three-inch-long (eight-centimetre-long) plant-hopper also has eyespots on its wings. If both these tricks fail, it can also emit a foul, skunky odour for the ultimate turnoff.

(Triple bonus points if this guy made you think of that They Might Be Giants song about prosthetic foreheads.)

2. Skipper Butterfly Pupa

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The skipper butterfly pupa’s fearsome face.

This amazing face is definitely a great fake-out. But it’s not a second face because it’s on a pupa, which doesn’t really have a face - at least not on the outside.

Biologist and conservationist Daniel Janzen discovered this pupa of Cephise nuspesez, a Costa Rican skipper butterfly. In a 2010 paper on counterfeit eyes, he writes that in this case, there’s no need for a face-making pupa or caterpillar to mimic a specific predator perfectly.

That’s because the false face-maker just has to look alarming enough that a bird won’t take any chances, leaving the insect to live another day and the trait of the false face to be passed on.

The face is supposed to say to the bird: “You are very close to becoming lunch, flee, NOW,” Janzen said in an email. (Also watch a video about a snake with a tail like a head.)

3. The Happy Face Spider

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A happy face spider guards her eggs.

When you find out they live in Hawaii, it’s easier to understand why the happy face spider is happy.

But a happy face is not the only pattern displayed by the happy face spider. The species can come in different patterns - they can look more like your 1970s smiley face with just a line for smile, have a large red grin, have no smile at all, or even appear a little frowny.

The face is thought to keep predators at bay, but one has to wonder…does it work for the usual reasons or do they decide it’s just too cute to eat?

4. Draculas gigas

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The monkey-face orchid mimics a mushroom.

It’s easy to see the simian features in Draculas gigas, sometimes called the monkey-face orchid (though that label is applied to several species). But what’s less obvious is why it bothers.

Fish and insects might evolve eyespots to startle predators, but why would an orchid need to ape an ape?

Answer: It wouldn’t.

Ron McHatton of the American Orchid Society writes in an email that “the face that you see in D. gigas is more of a coincidence than anything else. Orchids are incredible mimics - fragrance as well as appearance - and it’s really all about attracting the pollinator.”

Which, in this case, are fungus gnats and insects that eat them. What the orchid does mimic is something to attract those fungus gnats: Its lower lip is frilled like the underside of a mushroom, and it gives off a musty, mushroom-like odour.

So the flower has evolved a deception, just one we don’t notice - possibly because we can’t stop staring at that monkey mug.

5. Twinspot Goby

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A twinspot goby in Papua New Guinea.

Between its disguise and its numerous aliases, you’d think this fish was in the witness protection program. It goes by the names eyespot goby, crab eye goby, signal goby, or four-eyed goby, but it can always be called Signigobius biocellatus.

This species also keeps you guessing about where its face is. Two large black eyespots on its dorsal fins can make it look like a scarier fish than it is; its true identity is as a peaceful bottom feeder.

Another benefit to those eyes is that you can’t sneak up on a twinspot goby - or at least, the goby makes you think you can’t. Watch this video of a twinspot goby literally making itself new digs: When it backs out of the hole, it looks like a potentially much larger fish coming out face-first. Talk about eyes in the back of your head.

Catdog approves.

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[Source: National Geographic. Edited.]


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