Springtime at the Ponds

Text and photos by Michael Wilpers, Natural History Committee Chair

On Saturday, April 29, 2007, about ten adults and three children joined aquatic ecologist
Chris Sargent in the Kemp Mill area to explore life in the stormwater ponds and nearby creek.

One of the first things we found was a Fisher Spider, a member of the spider family that doesn’t build a web
but instead tracks down its prey by swimming underwater. It surrounds its hairy body with an air bubble
for breathing, allowing it to stay below for more than half an hour.

Scooping out water and mud with nets, and depositing them white basins, we examined the tiny fauna in the pond. Many American Toad tadpoles were swimming about along with a few damselfly larvae. Both animals spend the first part of their lives as water creatures, and then metamorphose into very different-looking adults that live on dry land. Eventually, they return to the water to reproduce.

American Toad tadpoles

Damselfly larvae

Our nets also pulled up tiny eggs attached to vegetation.

Using a hand-lens, Chris identified them as fresh-water snail eggs.

When we emptied the basins, we could see the narrow slime trails left by adult snails
wandering around the bottom.

As we headed away from the ponds toward the creek, we noticed a dragonfly at rest on the ground. It was an immature male Common Whitetail, whose abdomen had not yet developed its characteristic white color.

Further upstream, Ed Murtagh showed us the spot under exposed tree roots where he had seen large tadpoles.

He retrieved one that Chris identified as a Green Frog tadpole, a species our FrogWatch team had not heard calling in the past three years. It is unusual to find them in moving creek waters, but they may have swum there when the ponds backed up during a storm.

Upstream another hundred yards or so, we visited one of our vernal pools (small bodies of water that are unconnected to any stream and are wet only part of the year). We found a salamander egg mass.

The tadpoles had already emerged from most of the eggs, save a few that had failed to hatch.

We wound up at Ed’s house, where Chris used her digital microscope to look more closely at the Green Frog tadpole. It was easy to see the developing legs, just emerging along the animal’s skin. She also showed us how the ridge pattern on the tadpole’s “face” is used to determine the species. The natural history committee plans to acquire one of these microscopes, as they are quite affordable and a great teaching and research tool.