If you walk through woods or meadows this time of year in almost any part of Georgia, you’re likely to come across small wetlands temporarily filled with water from rain or ground seepage.
They usually are shallow — not more than a few feet deep — and may be as small as a good-size puddle or as large as an acre or more. They aren’t connected to a stream or other permanent water body, which is why they are often called “isolated wetlands.”
Other names for them are vernal pools and ephemeral ponds, because they hold water only part of the year.
By mid- to late summer, most of them will be dry, because of intense heat and lower rainfall. Those conditions and their isolation make the wetlands inhospitable to fish — a major reason that the small, temporary bodies of water play vital roles in the survival of several species of frogs and salamanders.
The amphibians lay their eggs in late winter or early spring in the fishless pools. After hatching, the larvae remain in the ponds for several weeks to a few months to feed and transform into adults.
Fish, if they were present, would quickly gobble up the eggs and young. But, being free of fish, vernal pools provide safe havens for a variety of vulnerable young frogs and salamanders.
One of them is the mole salamander (Ambystoma talpoideum), which occurs across most of Georgia. Mole salamanders spend most of their lives in underground burrows. On rainy nights in winter and early spring, they emerge to journey to a vernal pool, where they mate and lay eggs before going back underground.
The eggs hatch during late winter and early spring. As early as May, the young will have matured enough to begin leaving the pool.
Some other common amphibians that also depend on vernal pools during their life cycles include the marbled salamander, the spotted salamander and the wood frog.
For most of the vernal pool breeding species, their larvae are in a race against time to transform into adults — the young must get through the transformation process before the ponds dry up.
In the sky: From David Dundee, Tellus Science Museum astronomer: The moon will be new Thursday. Mercury is low in the west at dusk. Brightly shining Venus rises out of the east less than an hour before sunrise; it will appear near the moon Wednesday morning. Mars rises a few hours after sunset. Jupiter is high in the east at dusk. Saturn also rises out of the east at dusk.
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