THE FANTASTIC FREEZING FROGS OF NORTHEASTERN PA By Kathy Dubin-Uhler, Director of the Pocono Wildlife Rehabilitation Center
I
love the first days of spring. The vernal equinox is a day of celebration for me overshadowed only my wedding anniversary and the last day of school. The latter part of March brings brighter sun, the rich aromas of organic decay, and the calling of our earliest spring frogs. Life, it seems, is renewed… and more than figuratively at that. There are three species of frogs in the Poconos that literally do “come back to life”. The Wood frog, Gray tree frog and Spring peeper burrow under the leaf litter in the fall and literally freeze until the ground thaws in the spring. It’s a feat of nature that we are just beginning to really understand and can reproduce in humans only in science fiction movies. Special proteins cause the water in the blood to freeze first. This ice sucks most of the water out of the frog's cells. If water inside cells were to freeze, it would break them open, killing the frog.
54 POCONO LIVING MAGAZINE© FEBRUARY/MARCH 2022
WOOD FROG
At the same time the frog's liver starts making large amounts of glucose, the same sugar we burn for energy, which packs into cells preventing their collapse and freezing. This syrupy solution helps prevent any more water from being pulled out of the frog's cells, which would destroy them. Humans lack these special proteins. So when our skin freezes, we get frostbite, which sucks all the water out of our cells and causes them to collapse. Even after thawing, it's too late. All the cells are broken Spring peeper because humans haven't made all that sugar. The frogs, however, enter a state of suspended animation. Inside the cells there's thick sugary syrup, while outside the cells all the water is frozen. They may stay like this for months at temperatures down to 20°F. The heart stops and there is no brain activity. When temperatures warm and the ice melts, the frogs thaw. Water
