Jimmy Cooley, age 8, of Springfield, S.D., for his question:
How do hibernating frogs breathe in the mud?
Winter cavers wide stretches of our land with blankets of snow. In same places the creeks are covered with ice. There are no bugs to bother us, most of the birds have gone and many animals are hibernating. Some of the frogs and toads are asleep in the frosty ground, some under stones or logs and some are buried in the mud below the icy waters of creeks and ponds.
We share our country with about 90 different kinds of frogs and toads, and not one of them can abide the chilly winter season. They are cold blooded animals that get their warmth from the air and the ground around them. Their bodies need this outside warmth to keep going. In frosty weather, these cold blooded creatures become slow and too tired to move.
In late fall, the various frogs and, toads feel very hungry. They devour more food and grow plump. As the weather gets cooler, they became tired and each one seeks his winter quarters. The bullfrog who hatched last spring is still a tadpole, though the drab green fellow may be five inches long. He sinks to the bottom of the chilly water and buries himself in the mud.
Most frogs grow from the tadpole to the graven up stage during one summer. In winter, some of these frogs also bury themselves in the mud below creeks and ponds. Same frogs find winter homes under logs and stones. The toads dig themselves dawn into the soil about a foot below the surface. When the frosty weather arrives, all these creatures have fallen into the deep s1eep Of hibernation.
This special sleep is very different from our night time sleeping. It is deeper even than a faint or coma. The hibernating frog does not move at all and his little heart almost stops beating. He does not use his nostrils and lungs for breathing at all.
However, the hibernating frog does need to have a little oxygen. But he is an amphibian, and every amphibian has a most remarkable skin. The skin of a frog can take in oxygen from the air or from the water. There is dissolved oxygen in the soil and mud, and it can pass right through the frog's skin into its tiny veins. A hibernating frog needs only a little oxygen to keep him going through his long sleep. There is enough oxygen in the mud at the bottom of a chilly pond and some of it passes through the frog's skin into his body.
The little green pepper frogs wake up with the first breath of spring, and by April all the hibernating frogs are wide awake and very busy. For the grown ups, it will soon be egg laying time. But the bullfrog who hatched last spring is still a tadpole. He will spend most of the summer growing into an adult frog, and he will not become a parent until he has hibernated through another winter.