Mustache seals are an invaluable tool in hunting animals in the dark cold waters. Now, a new analysis has shown that these seal whiskers are sensitive enough to allow the animal to determine the shape of the object on the swell, which he leaves in the water.
By studying the behavior of the 12-year-old seal named Henry, the researchers found that feeling only trace of the object that moves through the water, the seals can detect the difference of its size to 3.6 inches. Henry also could tell the difference between a flat paddle and a triangular, ribbed or cylindrical.
Such abilities, as noted by Hank Wolf (Wolf Hanke), study researcher from the University of Rostock in Germany. In the earlier study it was found Hank that seals able to trace the path passing fish up to 35 seconds after the fish disappears from view. With such an amazing sensitivity mustache and the ability to swim underwater in a dark environment, it is not surprising that the seals can also determine the shape of the object in the water ripples, which he leaves behind.
"This should be an important condition for the seals, which need to be addressed, whether it makes sense to pursue a fish or some other interesting thing" - Hank said. In order to test the ability of the seal Henry distinguish shapes, the researchers first put on a blindfold and ear animal to isolate it from any sound. Henry, according to Hank calmly reacted to the bandage on his eyes, as if not to see the animal was "quite a common thing."
Henry then placed in a sealed plastic box at the pool where he swam. Hank and his colleagues moved the paddles of different shapes and sizes on the water box, allowing Henry to feel his mustache ripples formed by the movement of the oars. After the animal has felt the ripples from one subject, the researchers created a ripple of movement hilarious another form. Seal taught to touch a small plastic box ball, if he could announce that a new ripples on the water is different from that of the animal felt before.
When the paddle moving at the same speed, Henry could not tell the difference relative to the size of objects up to 3.6 cm Even when the paddle moving at different speeds, Henry could still get information on the ripples that pointed to the difference in the size of oars equal to 4.4 cm
Seal could not be clearly distinguished from each other by the shape of each paddle, but he could tell from the flat paddle swell from all other forms of 80 percent or more than once. He could also tell about the difference between a ribbed cylindrical paddles with a precision of better than 60 percent. "This is very interesting, as it was previously known that this sensor system is used to find things. But first, researchers have never known that it helps animal analyze things "- concluded Hank. "This opens the door to a series of studies subject differences."
Original: LiveScience Translation: M. Potter