A closer look at the wild things in a New England back yard and beyond
Wednesday, June 2, 2010
Leopards in the Grass
Leopard frogs (Lithobates pipiens), that is. I took a group of first graders on a hike yesterday to learn about ecosystems and and they were thrilled to see so many leopard frogs. I wasn't sure if frogs were going to be exciting enough for them since the list of animals they told me they expected to see before we began our hike included bears, pandas, moose, and platypus. Sorry kids, not today!
But they were thrilled with the frogs, toads, insects and pond creatures they found. One little boy told me he'd never seen a live frog before so he was especially excited (he was the one who mentioned the possibility of spying a platypus in the Ipswich River).
We found the two pictured above beside the vernal pool. The frog in the top photo appears gravid. Once they've bred and laid their eggs, the leopard frogs will move out into the surrounding woods or grassy meadows where they can feed on insects. One child in the class caught a leopard frog in the grassy field where he was sweeping for insects.
Depending on the weather, the eggs will hatch on average in about 15 days. Metamorphosis takes about 11 weeks. The juvenile frogs then head out toward areas with tall vegetation. Once winter comes, leopard frogs return to the water to hibernate until spring.
Click here http://www.yale.edu/peabody/collections/vz/her_leopard.html to hear a sample of one of the leopard frog's calls. Like many amphibians, northern leopard frogs are highly sensitive to the conditions of the environment and may exhibit physical deformities such as extra legs in response to pollution. In some areas, especially Canada, populations of northern leopard frogs are declining.