[SciShow intro plays]

Michael: You learned it in picture books and preschool: cats meow, dogs bark and ducks quack, but not all animals use such obvious methods of communication, and some of them are downright weird. From ultrasound to headbanging to piles of poop, these animals have all kinds of unusual ways to talk to each other.

Up first we have the African Elephant, a very large creature that uses very low sounds to communicate - so low that humans can only feel them as rumbling vibrations.

They use infrasound, sounds with frequencies below 20 Hertz, which is the lower limits of what humans can hear. This lets elephants communicate across incredibly long distances through these vibrations through the air and ground - up to 285 km² by some estimates.

Different atmospheric conditions can affect just how far these infrasonic calls travel - things like wind and heat can disrupt the sound waves and make the range much smaller. So researchers have observed that these elephants mostly communicate around sunrise and sunset, when it's cooler and the air is calm.

These long distance rumbling calls let different groups of elephants hear and feel where their neighbors are, so they can plan their grazing routes accordingly.

And elephants live in groups split by sex: females gather with their babies and are led by a matriarch, males on the other hand either wander alone or in small groups of other males. So, when a female is ready to mate she has to be able to find a male across miles of savannah. So it turns out that some of these infrasonic calls are basically elephant booty calls.

On the other end of the spectrum, we have the tiny, adorable tarsier. These miniature primates live in South East Asia, and they're about the size of your hand, with big ol' eyes. And they also communicate at a frequency that humans can't hear, way up in the ultrasound range, over 20 000 Hertz.

Ultrasound is pretty rare in the animal kingdom, besides animals like bats who use it for echolocation, so scientist were surprised to discover that tarsiers use it all the time. They'd observed these tiny primates opening their mouths kind of like they were shouting but they seemed to be silent. It wasn't until one researcher decided to listen to them with a device for recording bats that anyone figured it out.

Tarsiers make vocalizations at around 70,000 Hertz, and seem to be able to hear sounds up to 90,000 Hertz. Researchers think these calls could help tarsiers communicate over the background noise of the rest of the jungle, and avoid predators since most animals can't hear sounds anywhere near that frequency. Plus, they could hone in the high pitched noises of certain insects which makes it easier to hunt down dinner.

Prairie dogs are very social critters, living together in underground cities. They've developed a seriously complex system to keep each other informed of what's going on near by. We consider language to be an essentially human thing but these prairie dogs are turning heads in the scientific community.

Scientists have been recording and analyzing different sounds that prairie dogs make. And they've discovered that they have distinctive calls for different kinds of predators. So they make a different for a hawk than say a coyote or a domestic dog or a human.

During their study researchers noticed that there was also a slight variations in the call for a human for example. They wondered if it was possible that these calls weren't just identifying nearby predators, but actually describing them.

So they did a test where they had a couple human volunteers all dress exactly the same, except for the color of their shirt, and then walk across the prairie dog village. When they analyzed the calls, they naturally grouped together based on the shirt color the humans were wearing. So the prairie dogs seem to be able to tell the difference between a human in a yellow shirt, and a human in a blue shirt, and communicate that information to their neighbors. Not only that, but there were similar calls for other characteristics too, like tall or short humans.

It's not totally clear to us how prairie dogs interpret and understand this information. So unfortunately we don't know most of what they're saying about us, yet.

The African demon mole-rat. Sounds pretty hardcore, but they don't look particularly frightening. Turns out these fuzzy little guys are actually pretty metal. In fact they use head-banging as a way to communicate.

Down underground vision and normal hearing won't get you very far, there's not enough light and sound waves don't travel very well through dirt. And many species of mole-rats live in social groups but the demon mole rat is a pretty solitary little guy.

So in order to talk to their neighbors and protect their territories, these mole rats use seismic communication. By thumping their heads against the tops of their tunnels they send vibrations that can travel much farther through the earth. Scientists think different patterns of head-banging signal different things

Like a slower pattern could be a warning or a disturbance or a possible threat, and faster patterns seem to signal an animal's identity to it's neighbor. Like "Hey I'm here, back off." No word yet on whether they have a special pattern for getting a mosh pit started though.

We've known for awhile that different species of marine mammals, like sperm whales, have adapted complex communication systems. This is part of the social complexity hypothesis which says that as a species' social structure becomes more complex, so does their communication. So different social groups can have a different sounds or even region specific accents of a sort.

Sperm whales for example use repeating motifs of clicks called codas to talk to each other. Whales is different regions of the ocean use very specific patterns of clicks, kind of like an accent. So Caribbean sperm whales will have a coda of one pattern, while a sperm whale in a different region will arrange their clicks differently.

Even within a region things can get more complex. Scientists have found that some whales have sounds that can identify individuals in family groups. Kind of like how we use first and last names. These kind of communications are probably important for reinforcing social bonds, and researchers think this could be evidence that these animals have a culture. So it might not be that long before we're learning to speak whale, just like Dory.

It's pretty common in the animal kingdom to use poop and urine as signals like: "this is mine," or "stay back," but for some species like white rhinos it's crucial for group communication. These rhinos have poor eyesight which led researchers to think that smell might be extra important to these animals. And not just to mark territory.

It turns out that groups of white rhinos will use communal dung heaps called middens as a sort of big stinky message board. Rhino poop can paint a picture of an individual animal's health. So rhinos can visit these 3 meter wide dung heaps to get a whiff of what's going on in the region. Like if any rhinos are sick, whether or not a female rhino is ready to mate, if there's a new kid around, or if a dominant male has visited recently.

Scientists found that rhinos spent more time sniffing the poop of unfamiliar rhinos than that of their family and friends. Which seems to suggest that they can identify individuals based of some of these scent markers. So it turns out that the steamy neighborhood gossip for rhinos, is literally a big 'ol pile of poop.

Caribbean reef squid use specialized cells that contain pigments and light reflecting molecules called chromatophores that change the color of their skin to send different messages. Usually squid and octopuses use this color changing ability for things like camouflage when danger is present. Or to put on a show to attract a mate.

But Caribbean reef squid have a different lifestyle than most other cephalopods. Rather than leading solitary lives these guys are unusually social and live in small groups throughout the Caribbean Sea. So they've developed the ability to manipulate their chromatophores for lots of different communication purposes; from hiding, to warning each other, or complex courtship rituals. Different colors, patterns and flashes send different messages. And they can even send one signal to a squid on their left side while sending a different signal to a squid on their right.

So a male could be fending off competition on one side and wooing a lady squid on the other. Talk about mixed messages.

Speaking of unique relationships, researchers have observed a very interesting collaboration between the coral grouper and other predatory marine species. Groupers will try to grab a bite to eat on their own but sometimes their prey will dive into the cracks of the coral reef, where the groupers can't reach them. So they'll wait around for another fish to come along, specifically either a Napoleon wrasse or a Moray eel. And use a kind of sign language to ask for help in hunting down dinner.

Basically the grouper will point it's nose at the hidden fish and shake it's body side-to-side. Signalling the presence of prey, then either the wrasse will smash into the reef to get at the prey, or the eel will creep into the cracks and try to grab it. Sometimes the wrasse or the eel catch the prey and get a meal for themselves, it's a fish-eat-fish world out there so they don't share with the grouper and it's just out of luck.

But other times the prey tries to escape by fleeing the reef, giving the grouper another shot at nabbing it's dinner. By combining their different but complimentary styles of hunting it ends up being a pretty beneficial relationship. With the help of a little extra communication and body language, all three of them have a better chance at catching something to eat.

And there are other animals that communicate across species. One genus of butterfly called Maculinea rely on Myrmica ants to care for their caterpillars. This sounds kind of friendly, but like lots of things in nature this relationship can get deadly.

Because ants use a lot of chemical signals to communicate, researchers think these caterpillars are coated in something that imitates the scent of the Myrmica ants. Plus Maculinea caterpillars have evolved the ability to make noises similar to an ant queen. Also they can trick the ants into bringing them back to the nest.

And once they make it there, two species of Maculinea have different survival strategies. The predatory variety sings just long enough to get the ants to bring it into the nest. And once it's there it goes silent and finds a secluded corner to hide in. This caterpillar preys on ant larvae so it hides out like an assassin emerging only to binge on baby ants when it is hungry. On the other hand, the cuckoo variety sings even louder once it's in the nest. Which somehow motivates the ants to feed and care for it live one of their own larvae. In one experiment scientists found that the ants would even rescue the caterpillar before their own larvae when the colony is disturbed. That must be some some pretty impressive singing.

So while human communication is incredibly complex, it turns out that animals have a lot of strange ways to talk to each other too.

Thanks for watching this episode of SciShow brought to you by our patrons on Patreon. If you want to help support the show just go to Patreon.com/SciShow, and don't forget to go to YouTube.com/SciShow and subscribe.