“The eyes of all wait upon thee: and thou givest them their meat in due season.”
Shore birds like the oystercatcher search for buried mollusks by touch. They poke around in the sand, hoping to find a hard-shelled mollusk. But if you have ever tried to find something that was hiding where you couldn’t see it, you know that this method of looking for something is not very efficient. But another shore bird, the red knot, seems to know just where to find its hidden food.
Scientists observed that the red knot, a type of sandpiper, was seven to eight times more efficient at finding buried food than it would be if it were randomly searching. Red knots, who also search for food by pushing their bills into the sand, did better than those birds who search by touch.
The answer didn’t come until scientists looked at the red knot’s bill under the microscope. On the top of the bill they found tiny pits. Inside the pits they found cells called Herbst corpuscles. Scientists knew that other shorebirds have organs similar to these corpuscles that are used to feel vibrations from wriggling prey. They theorized that the red knot’s Herbst corpuscles sense pressure changes in the displaced water under the sand when a mollusk obstructs the water’s flow. Next they tested captive birds who were trained to find mollusks in pails of sand. Scientists found that if the sand was dry, the red knots did not do very well. But when the sand was wet, the red knots could indeed find the hidden mollusks.
God’s creative nature and divine wisdom has provided His living creatures with a beautiful variety of ways of making their living.
I praise You, dear Father, for the variety You have given us. Amen.
S.M., New hunting trick explains bird luck, Science News, v.154, p.107. Photo: Red knot. Courtesy of Jan van de Kam. (CC BY 2.5)