Dolphins have a pretty amazing way of handling the problem of finding food and finding their way around in the oftentimes murky lightless depths of the world’s oceans – sonar. A lot of folks like to refer to this as echo location, which is really more of a description. Either way though, this is some pretty cool technology that dolphins have been wielding and working out the kinks on for some twenty million years!
Basically, dolphins send out a series of sounds – often heard by us as clicks and squeaks. Sound moves 4 times faster in water than it does in air, so navigating by sound makes for a pretty effecient way of doing things. Once the sound hits an object, the sound waves then bounce back. This is why people call it echo location. Humans can hear echos of course, but we sure can’t navigate by it. Dolphins on the other hand are able to Pick out an object the size of an orange from nearly 80 meters away. For those that don’t live in metric world – that is a whopping 262 feet! At shorter distance they are able to differentiate between a BB and a kernel of corn!
Dolphins therefore have a highly adapted way of perceiving sound. To give you an idea of this, humans can hear sounds as high as 20Khz. Dogs on the other hand can hear up to 45 Khz. This is why a dog whistle is completely silent to humans as the sound is to high of a frequency for use to pick up on, but dogs love it. Now a dolphin on the other hand can hear up to an amazing 120 khz with echo location! That’s 6 times what a human can hear. In order to accomplish this feat however, dolphins are not using ears like dogs and humans. Instead, dolphins, like all members of the family of toothed whales (known as odontocetes), have developed a highly specialized type of blubber known as acoustic fat. This fat is what makes up the big giant forehead on dolphins for which the clicks and pops are coming from. Along their lower jaw, they have another strip of this acoustic fat for which is designed to receive the echo coming back at the dolphin. Now just how dolphins are able to interpret what they hear with this biosonar, we have pretty much no clue. This is one of the great mysteries of marine biology which is one of the reasons that dolphins are so fascinating to us.
Dolphins are a regular sight on our tours. With thousands of these amazing creatures calling the coast of the Outer Banks home during the summer months, chances are, you will have the opportunity to see and learn all about these little whales!