Busy Morning at the Vernal Pool

While all of the wood frog and spotted salamander breeding activity has come to a close in our vernal pool, there is still plenty of life to observe. We had a great outing during block one today checking in at our pool. Our basic mission was to return some of our classroom wood frog tadpoles in order to keep our tank from overcrowding. Our tadpoles were brought in as eggs early last week and have grown rapidly ever since. The ones returned to the pool this morning have gotten a notable head start on their brethren who have remained in the pool. They are equivalent in size to where they would naturally be in June. This gives these lucky individuals a better chance at reaching metamorphosis before the pool dries up mid-summer.

Wood frog tadpoles ready to be returned to their natal pool

I brought my new camera along for the walk this morning which up until this point has seemed more like wildlife repellent than a useful blogging tool. I'm glad I did as we observed several cool vernal pool visitors. The first sighting was of a beautiful american bittern (Botaurus lentiginosus). Luckily for us, this secretive bird fluttered up into a bush and struck its "concealment pose", doing its best dead stick imitation. Had it just remained motionless at the edge of the pool we never would have seen it. Bitterns are heron-like birds that wade quietly in the shallows feeding on frogs and small fish. To an american bittern, a vernal pool is an all you can eat buffet. Perhaps the coolest feature of the american bittern is its low pitched breeding call. This sound is often described as a rock dropping into the water and is achieved by gulping air into its esophagus.

An american bittern striking its "concealment pose"

After spending a few minutes sitting quietly and observing the pool as a class, amphibians began to appear seemingly out of nowhere. First came a green frog (Lithobates clamitans) resting along the edge of the pool.

A green frog along the edge of the vernal pool

Finally, an especially observant student spotted a spring peeper (Pseudacris crucifer) clinging to to some vegetation in the water. Spotting a spring peeper without it moving first is a feat few can claim. These tiny tree frogs have amazing camouflage and while impossible not to hear this time of year, they are rarely observed.

 A secretive spring peeper in the vernal pool.

Note the sticky toe pads and diminutive size of this adult peeper