December 7, 2021

I, Science

The science magazine of Imperial College

We humans know how to tell a white lie or two. But what about the rest of the natural world? Here we take a look at ten of the most intriguingly deceptive creatures on the planet.

1. Green-eyed brood sacsnailThis parasitic flatworm, found in intermediate hosts such as snails in Europe and North America, uses aggressive mimicry to survive-a type of camouflage that allows predators to appear harmless to their prey. By infecting snail host’s eyes, they appear as brood sacs that swell and pulsate in green, yellow and red, mimicking a caterpillar or maggot. It is thought that the infection of the tentacles of the eyes seems to inhibit the perception of light intensity, meaning that infected snails seem to have a deficit of light detection. A study carried out in Poland showed that there was a tendency for infected snails to stay in open places for longer and sit on higher vegetation, leaving them susceptible to predation and continuing the flatworms life cycle within a new host, the bird.

You can watch this bizarre behaviour here.

2. Male sea otters sea ottersOff the coast of Southern California, male sea otters prey on the maternal instincts of females to attain food – by ‘kidnapping’. While female otters are out scavenging for food, leaving their young nearby, the male approaches, takes the baby and holds it hostage. Hearing her baby’s cries, the female otter returns, food in mouth, but the male does not let the baby go until he is given the food, at times going as far as nearly drowning the pup.

3. Cinereous mourner bird chick with crazy feathersYou would not look twice at an adult cinereous mourner due to its predominately grey colouring, but its chicks harbour a deceptive secret. By sporting bright orange feathers and black polka dots, they mimic an entirely different species in the nest. A researcher at the ICESI University in Colombia, noticed that when chicks were disturbed, rather than crying out for food like most other nestlings, these chicks bobbed their heads in a slow winding motion, much like a caterpillar. Although advertising yourself as a potential caterpillar meal does not sound like the best idea, it certainly could be when the hairy caterpillars in the vicinity are known to be toxic.

You can watch a clip of this strange behaviour here.

4. Mimic octopus octopusThis Indo-Pacific sea dweller, first observed in 1998, is a master of disguise. Almost 10 disguises, in fact. Although many animals have been observed imitating different species to escape predation, this small octopus is the only one that can imitate a whole range. Animals that it can imitate are incredibly variable too- it has been observed mimicking a squid, a jellyfish, a flatfish, a lionfish and even a sea snake. One of the major findings of scientists was that although they can disguise themselves in aggressive mimicry in order to attack potential prey, they use the skill primarily as a defence mechanism, particularly in areas were movement would give away their otherwise camouflaged appearance.

Watch this master of disguise in action here.

5. Flower mantisflower praying mantisPraying mantises that have evolved to look like flowers in the wild also use aggressive mimicry to survive. Found in the warm climates of South Asia and Africa, a flower mantis perches motionlessly on twigs or tall plant stems until an insect gets close enough for capture. It also uses this as a defence mechanism when its own predators approach.

6. False cleaner fish one small fish next to one large fishThis duplicitous fish, a species of blenny, is indigenous to coral reefs in the Indo-Pacific. Cleaner wrasses are known for their symbiotic behaviour, cleaning larger fish of parasites and dead skin thus receiving a meal in return. The false cleaner fish however, is not so considerate. It mimics the shape, markings and behaviour of the hard working wrasses and takes advantage of the trust instilled in them by the larger fish, who open their gills for more effective cleaning. It is then that the wrasses attack, snatching a bite of the trusting fish and making a swim for it. It is a double edged sword too- the breach of trust is likely to make the larger fish more wary when it comes to his next clean!

7. Deep sea angler fishangler fish The anglerfish is an ugly devil. Mostly head, its huge jaws dominate its front half and extend to increase capacity, something its stomach does too, in light of the unpredictability of frequency and size of prey half a mile down. The most widely recognised feature of a deep sea angler fish however, is worn only by the female. A piece of dorsal spine protrudes above their mouths like a fishing rod and bioluminesces, a result of symbiotic bacteria which fluoresce within the tip. In the lightless depths of the sea, the light acts as a lure, enticing prey towards it before promptly guzzling it lest a chance for eating be missed. Bon appetit!

8. Long-tailed macaques macaque at zooMonkeys in the popular tourist areas of Indonesia have developed a way to deceive not other animals, but humans. In heavily populated streets filled with food stalls, these monkeys have grasped the concept of bartering in lieu of stealing food. Watching tourists carefully, the animal quickly approaches them, stealing items like their phone or sunglasses. Not running very far out of reach, it perches on a nearby ledge with the item in hand, waiting for the owner to approach. It only drops the item when presented with desired ransom – usually high-protein food.

You can follow the mischievous actions of one of the monkeys here

9. Fork-tailed drongodrongo bird on branchThe drongo, common to parts of South Africa, not only deceives other animals upon first meeting, but gains their trust beforehand. Throughout most of the year, the drongo acts as a ‘watch bird’ for meerkats and other bird species. When it sees a potential threat, it chirps a call and the animals retreat to safety, forming a symbiotic relationship. However, during the colder months in South Africa, when food is harder to come by, the drongo chirps the danger call when there is no potential threat, only to swoop down seconds later and eat the food left on the ground. The meerkats can only be fooled so many times by this false call though, so the drongo can also imitate the danger-call of another meerkat to make them flee.

10. Burrowing owlsowl in front of burrowFound in the Americas, burrowing owls live underground in deep burrows instead of in trees. In order to feed their young, female burrowing owls collect mammal dung and drop it near their nests. Insects, spiders and other small creatures are attracted to the smell of dung and migrate towards the burrows. One by one, the owl pecks them up, feeding them to her young. She spends most of her day collecting these vermin for her offspring.

Sophie Walsh and Cheyenne McCray are studying for an MSc in Science Communication.

Images: Green eyed brood sac, D. Kucharski K. Kucharska; otter, worldswildlifewonders; cinereous mourner,; mimic octopus, Luke Suen; flower mantis, Sebastian Janicki; cleaner fish, Stephan Kerkhofs; angler fish,; macaque, Mariia Smeshkova; drone, Alta Oosthuizen; burrowing owl, Don Mammoser.