How Sensitive Are Walrus Whiskers?
Walrus have a lot of whiskers because they need to search for food on the seafloor. Unlike other Pinnipeds that eat fish, Walrus eat mollusks and other creatures that live in the seabed. Because their eyes are placed on the side of their head, Walrus have a difficult time seeing their food, so they have to use whiskers to feel for their food.
How sensitive are Walrus whiskers? Around 30 years ago, a group of researchers did an experiment to find out. First, the researchers trained a Walrus to nod if he felt a triangle or shake his head if he felt a circle when nuzzling a board with a triangle shape on one side and a circle on the other side. The Walrus had earphones over his eyes so that he couldn't see the shape, and the researchers would know that the Walrus was feeling the shape with his whiskers and not looking at it.
After the Walrus could reliably tell the researchers that he knew the difference between a circle and a triangle, the researchers added sand to the board to better simulate the seabed, and made the shapes smaller and smaller until the Walrus could no longer report what shape he felt.
Photo of a Walrus feeling for the target shape, from the paper "The Tactile Sensitivity of the Mystacial Vibrasse of a Pacific Walrus (Odobenus rosmarus divergens). Part 2: Masking"
The researchers found that the "blindfolded" Walrus could feel a triangle or a circle down to smaller than the size of a pencil eraser. It took the Walrus about 1 to 2 seconds to figure out what shape was on the board.
How small of a shape a Walrus can feel, from the paper "The Tactile Sensitivity of the Mystacial Vibrasse of a Pacific Walrus (Odobenus rosmarus divergens). Part 2: Masking". Everything to the left of the line is the size that a Walrus can feel.
As you can read, Walrus do not just have whiskers for cuteness. Their whiskers also help them eat!
How sensitive are Walrus whiskers? Around 30 years ago, a group of researchers did an experiment to find out. First, the researchers trained a Walrus to nod if he felt a triangle or shake his head if he felt a circle when nuzzling a board with a triangle shape on one side and a circle on the other side. The Walrus had earphones over his eyes so that he couldn't see the shape, and the researchers would know that the Walrus was feeling the shape with his whiskers and not looking at it.
Photo of training setup, from the paper "The sensitivity of the Vibrissae of a Pacific Walrus (Odobenus rosmarus divergens). Part 1"
After the Walrus could reliably tell the researchers that he knew the difference between a circle and a triangle, the researchers added sand to the board to better simulate the seabed, and made the shapes smaller and smaller until the Walrus could no longer report what shape he felt.
Photo of a Walrus feeling for the target shape, from the paper "The Tactile Sensitivity of the Mystacial Vibrasse of a Pacific Walrus (Odobenus rosmarus divergens). Part 2: Masking"
The researchers found that the "blindfolded" Walrus could feel a triangle or a circle down to smaller than the size of a pencil eraser. It took the Walrus about 1 to 2 seconds to figure out what shape was on the board.
How small of a shape a Walrus can feel, from the paper "The Tactile Sensitivity of the Mystacial Vibrasse of a Pacific Walrus (Odobenus rosmarus divergens). Part 2: Masking". Everything to the left of the line is the size that a Walrus can feel.
As you can read, Walrus do not just have whiskers for cuteness. Their whiskers also help them eat!
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