Thom Smith Watching for wood frogs

For some, it’s the first pussy willow that marks spring. Not me. I have seen them in all their fullness in January and February.  For others, it is seeing the first robin or bluebird. Not me. These birds are with us all winter. Yet others claim the spring peeper to be the true harbinger of spring. Not quite, but close. It is hearing the first wood frog issuing his quacking-like, mate-attracting song that marks spring for me.

Wood Frogs have always been kinder to early springtime frog enthusiasts. This frog does  not care about temperature, provided it is above 40 degrees, or if it is day or night provided some open water allows for mating and egg laying.

They spend winter below woodland leaf litter, protected from the deep-freeze during their long winter’s sleep by producing high concentrations of glucose, an anti-freeze.  The first warm rains call them to order. Listen for their “quacking” in woods where they will be calling from shallow ponds.

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“Frog and salamander movement is all based on temperature and rainfall,” explains Tom Tyning, Berkshire Community College professor and noted authority on amphibians and reptiles explains. “If it’s above 40 defrees but the ground’s still frozen, then only peepers and wood frogs will move — they have freeze-tolerance mechanisms that let them spend the winter just in the leaf litter on the forest floor. They can freeze and thaw several times a winter before getting going for the season.”

“Peepers, historically, have been heard every month of the year in New England. Once the ground thaws, and it’s above 40 degrees and it’s very humid or raining, then many of the spring amphibians (especially the vernal pool users) will undergo their great migrations (and sadly, many won’t make it across the roads).

“If it stays warm, but we have little or no rainfall, then wood frogs will migrate anyway, especially in the daytime. They can’t wait too long to get to the pools. They migrate, court, lay eggs, and leave the pool in a matter of a few days; typically less than a week. Then, the eggs have to incubate, embryos develop, then hatch, then try to simultaneously avoid predators and find food, then grow big enough to metamorphose before the vernal pool evaporates.”

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My first encounter with the wood frog was sometime in the 1960s, while looking for early spring birds. I was in the open woods of the Sheffield flats, thick with shrubs and young trees, when I heard ducks calling in the distance.

Heading toward the sound, I was stunned at how close the “ducks” were, yet I could not see them, and on my noisy arrival where I was sure they must be, they seemed to disappeared.

Somewhat frustrated, I sat on a log, and after a few quiet moments passed the “ducks” began quacking again, only they weren’t ducks but frogs — two inch beige-colored wood frogs with a dark, raccoon-like mask over the eyes.

For this species. successful breeding is a race against time, especially following a dry winter and equally dry spring. They need enough water in the snow-melt pools they favor for eggs to hatch and tadpoles to develop into froglets before the pool dries. In dry years they can lose all of their offspring.

These temporary woodland pools, called “vernal,” because they occur in the spring, have no outlets and usually fill because of melting snow and winter’s freezing rain.

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Of the 10 species of frogs and toads that call Massachusetts home, the best known, besides the bullfrog is the tiny Spring Peeper, less than an inch long. For anyone lucky enough to actually see a peeper, it is easily identified by its size and by the “X” marking on the back. Unlike the wood frog, peepers live in wooded wetlands, along shores of beaver ponds and almost anywhere shrubs and water mingle.

“They are deafening,” locals say. “They keep us awake. Don’t they ever stop?”

But for me peepers are a welcome reprieve from the winter doldrums, and it is always motivating to hear their first chorus, reminding me that a new season is at hand.

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The American Toad is another early spring songster that trills rather than peeping or quacking. Its continuous call or trill can last nearly half a minute, and together, a cluster of eager toads produce a pleasant din that appears to last for hours.

One of three toad species in Massachusetts, it is by far the most common and best known, and often found by gardeners, who should encourage toads, since they feed primarily upon beetles and moths.

And no, the toad doesn’t cause warts, though as anyone with a curious dog learns sooner or later, it does have poison glands to give it a bad taste to any predator, wild or domestic, dumb enough to attempt to eat or “play” with it.

 

In the photo at the top, a wood frog looks over a leaf. Wood frogs survive frozen beneath leaf litter and thaw as warmer weather arrives. Notice the brown band over its eyes resembling the mask of a bandit. Photo by Thom Smith

1 comment for “Thom Smith Watching for wood frogs

  1. Howard
    March 30, 2017 at 10:57 pm

    Good story! I enjoyed it very much — and learned plenty. Thank you.

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