- vernal pool at Beech Lick Knob–photo by Bette Dzamba
¬† ¬† ¬†I recently joined with some fellow nature lovers for an early March hike in one of the best remaining wild lands of the George Washington National Forest. ¬† Beech Lick Knob is a 17,000 acre tract of beautiful forest–some of it old-growth–that includes ridges and streams.
¬† ¬† ¬†The hike was a pleasure, and the day even included a major thrill. ¬†At one point in our walk, I caught up with some who had gone ahead. ¬†They were crouching next to a vernal pool (a spring pool that dries up as the season warms) near the trail. ¬†Because they were looking intently at the water, I also stopped to look. ¬†But all I could see were a few brown leaves dotting the water’s surface; ¬†I had no idea what was holding the others’ attention.
¬† ¬† ¬†As I neared the water’s edge, however, those ‘leaves’ came into focus. ¬†And they weren’t leaves at all, but frogs! ¬†Here and there, dotting the surface of the pool were brownish frogs, prone, hind legs splayed, all completely still. ¬† Suddenly one of them darted forward. ¬†Stillness again. ¬†Then another. ¬†Stillness. ¬†And another. ¬†These frogs were very much alive!
- frogs visible–photo by Bette Zamba
¬† ¬† ¬†Then one of our fellow hikers pointed out two frogs clasped together at the water’s surface, close to the edge where we were standing. ¬†The male held the female close from behind, using the ‘nuptial pads’ ¬†(thanks to fellow hiker Bette Dzamba for introducing me to this cute term!) on his ‘forearms’ to hold her close. ¬†The two held completely still until suddenly, still in a tight embrace, they darted down into the murk of dead leaves and mud.
Frogs mating–photo by Bette Dzamba
¬† ¬† ¬†A little research after the hike reminded me that frogs don’t actually mate in the ‘conventional’ way; ¬†the male does not enter the female. ¬†The male holds the female, as we saw, sometimes for days. ¬†And at some point during that long embrace, the female releases thousands of eggs in a mass. ¬†The male then, shoots sperm into the egg mass, fertilizing the eggs.
¬† ¬† ¬†As we all stood around the pool, discussing the mating habits of frogs, we noticed a spongy looking mass below the water’s surface, not far from our feet. ¬†It was perhaps six inches in diameter. ¬†Then we noticed another mass nearby, and another and another, here and there below the surface of the pool. ¬†I am guessing that these egg masses had been very recently laid because we saw no dark spots, or yolks, in them that would indicate developing tadpoles. ¬†Instead, the masses appeared to be undifferentiated blobs. ¬†
¬† ¬† ¬†Those eggs that survive to develop and grow will hatch 6-21 days after fertilization. ¬†And vernal pools, like the one where we witnessed so much action that day, are the perfect places for frogs to lay their eggs. ¬†Since vernal pools are seasonal, they do not support fish. ¬†Thus, frog eggs are relatively free from predation. ¬†And vernal pools are generally still waters, so developing tadpoles are not buffeted about.
¬† ¬† ¬†Suddenly, the frogs began to make sounds! ¬†But it wasn’t a call that was familiar to us. ¬†We all agreed that these calls resembled the clucks of chickens! ¬†Within a few minutes, the pool had gone from a silent place to one full of these chicken-like calls.
¬† ¬† ¬†Thanks to Bette Dzamba’s post-hike research, I feel confident that the frogs we observed were wood frogs. ¬† Everything Bette learned about wood frogs seems to fit with what we observed: ¬†wood frogs are brownish; ¬†the female is larger than the male; ¬†these frogs breed very early, usually from late-February to early-March; ¬†and the male’s call is described as a duck-like “cra-awk,” which is consistent with what we heard. ¬†
Wood frog–photo by John Howard
¬† ¬† ¬† What a treat it was to stumble upon this vernal pool at just the right time to see wood frog reproduction in action!–April Moore