<ring is here! On campus the soft “woosh” of Frisbees through the air attests to its arrival. A little bit further a field in the Carleton arboretum a much louder sound announces the arrival of spring. This sound is the chorus of frogs, which can be heard near any still body of water, particularly Kettlehole Marsh.
Frogs hibernate during winter, which makes the sound of their voices filling the air a sure sign of spring. Poetic language often describes spring figuratively in terms of an awakening. Frog’s emergence from hibernation can even more literally be termed an awakening. Hibernation, however, is more than just sleep. During hibernation frogs burrow into the ground or lie on the bottom of ponds and remain mostly inactive with all normal body processes slowed. They metabolize stored fat and gas exchange or respiration happens through their skins. Some species of frog in particular have transcended the realm of sleep and entered that of cryogenics. The Wood Frog is one of these species. Wood Frogs, which hibernate in the leaf litter of the forest floor, have evolved to produce a kind of antifreeze in their bodies. In the winter water is pulled out of the frog’s cells and replaced by this antifreeze. This process prevents damage to the frog’s vital organs during hibernation when it is quite literally frozen solid.
The Wood Frog is just one of six species of frogs present in the Carleton Arboretum. The other species include the Gray Tree frog, Western Chorus Frog, Cope’s Grey Tree frog, Bullfrog, Green Frog, and the Northern Leopard Frog. The Chorus Frog is the most vocal of these frogs and the one most likely to be heard by casual passers by at Kettlehole Marsh. The call of the Chorus frog can be recognized by its resemblance to the sound of fingers being dragged across the teeth of a comb. The Chorus Frog itself is a small frog. When gazing at a still and silent Chorus Frog it is hard to reconcile their appearance with the huge sound with which they fill the air. This difficulty, however, is a welcome one as it speaks to the number of frogs that have survived the winter to awaken into spring.
