Possibly, Like Bigfoot, This Tiny Primate Can Hear Ultrasonic Frequencies [Science]

Some Bigfoot researchers believe that game cameras emit ultrasonic sound and Bigfoots can hear them. They say it could be the reason why Sasquatch avoid electronic equipment in general.

Of course, this is all speculation, but a recent study by biologists at Humboldt State University show that at least one primate has the ability to communicate via ultrasonic frequencies.

According to Live Science, the Philippine tarsier was once considered one of the quieter primate species. Turns out, these primates were chit-chatting among themselves the whole time they were being observed. They were communicating in ultrasound, meaning they used frequencies that are too high for human hearing. While lots of animals from dogs to fish to insects can hear ultrasonic frequencies, it's much more unusual for animals, particularly mammals, to actually communicate at these frequencies.

A Gizmodo science editor summarizes the Live Science article:

Tarsiers are one of the smallest species of primates, growing to only about the size of a man's fist, and live exclusively on the Phillipine islands. What makes them special isn't their enormous, lemur-like eyes, but the frequency of their shrill calls that fall well beyond the hearing range of humans—or any other primate for that matter. "It turns out that it's not silent. It's actually screaming and we had no idea," Marissa Ramsier, an evolutionary biologist at Humboldt State University, told Live Sciences.

The human ear can pick up noises up to 20kHz. That's paltry compared to the 91kHz sounds a Tarsier can hear and less than half of the 70kHz sounds a Tarsir can make. That's 26kHz higher than the previous record holder, the 65kHz-hearing Bush Baby. In fact, those frequencies are very similar to the range that bats utilize.

A research team from Humboldt State made the discovery in the Phillipine wilderness—Tarsiers are highly endangered and struggle in captivity—by capturing six of the animals, placing them in sound-proof chambers, and conducting hearing tests. The Tarsiers were bombarded with noises of various frequencies while non-invasive electrodes picked up their brain activity. The team employed an ultrasonic microphone to capture the calls of 35 separate specimens and found that their calls range from 67 to 79kHz—ultrasound.

This adaptation may have evolved to allow the animals a discreet form of communication. Predators can't track them from their calls if the predators can't hear them in the first place. "It's this duel benefit," Ramsier said. "They can communicate without predators hearing them and also locate some potential food sources."

[via www.livescience.com]