We're all happy to reach the end of winter, but for frogs and toads, spring means a great deal more than it does for us. They have been in deep hibernation, their lives barely flickering.
Their body activities were reduced to the point at which frogs were able to stay underwater at the bottom of a pond. There they absorbed just enough of the water's oxygen through their skin to stay alive while their body temperature dropped to that of the water around them. In many ponds, this meant as cold as 33 to 35 degrees. A few frogs withstood temperatures even below freezing: so cold that ice crystals formed temporarily within their bodies.
The ice on the pond surface served as insulation, the water beneath it shielded from the still colder weather above. That was very important during that bitterly cold week we experienced in late January.
Toads and some frogs instead bury themselves in the soil, but their winter experiences were little different.
Despite this punishment, millions of frogs and toads lived through the winter and are enthusiastic about spring. They awoke from their catatonic hibernation rarin' to go, and they are letting not only their own kind but everyone else know it.
The woods are now indeed alive with what I am happy to call their music. If youngsters can crank up the decibels on their CD players, frogs and toads have every right to do so as well.
I enjoy standing on the boardwalks that run through preserves like Great Baehre Swamp and Tillman Marsh listening to them.
First, I hear a single call. It is a rapid ticking, exactly the sound you create by running your fingernail quickly up the tines of a pocket comb toward the short end - in that direction because the "creek" sound rises. There are about 20 ticks in each call, but I don't try to count them.
Others respond until the loud noise pulsates. These so-called "vernal choristers" are appropriately named chorus frogs.
I now also hear single whistled peeps. An individual frog will peep about once every second, but before long so many call that the sound is like shaken sleigh bells.
These frogs are also named for their calls. They are spring peepers.
A third frog song I have to seek out. Unlike those of the chorus frog and spring peeper, it doesn't carry very far.
There it is: a low, duck-like quacking that identifies my favorite of all the frogs, the wood frog.
Finally, I listen for American toads. Over the din of the peepers and chorus frogs, I hear it: a one-note but musical trill lasting 20 to 30 seconds. Just before the first toad finishes, another begins at a different pitch.
If you have time, you can look for these delightful little frogs and toad. Shine your flashlight where you think they are. Many will dive out of sight but a few usually remain in view. They need to keep their heads and throat above the surface, as it is their throat bladder that they inflate to issue those calls.
It will require patience to find them. I have even looked in broad daylight with little success. One trick that I hope to try is floating a small board in the water carrying a lighted candle on it. I am told that frogs will climb aboard, but I will believe this only when I see it.
Once you do find them, these anurans are easy to tell apart. The chorus frog's back is striped lengthwise; the two stripes on the spring peeper's back cross to form an X; the wood frog has a plain back; and the American toad's back is warty. The wood frog also has a distinctive black mask. The chorus frog and spring peeper are tiny, only about an inch in length; the wood frog and toad are slightly larger, about 2 inches long.
Once you master these four distinctive calls, you can add to your repertory the calls of our other, mostly larger frogs - the bullfrog's "jug-o'-rum," the leopard and pickerel frogs' snores, the green frog's banjo twang, and the gray tree frog's slow trill.
But first learn these four common swamp songs. They will add much pleasure to a walk near vernal pools on a springtime evening.