Springtime at the Pond

Conservation // March 11, 2015

“If you build it, they will come.” Although not the exact quote from the movie Field of Dreams, it applies at the Tree House. They are frogs, toads, ducks, and other wildlife that gather at a  stormwater basin built just above the upper parking lot of the Wissahickon Environmental Center. They use the water to find food, a home, or a drink.

In 2009, to reduce the amount of water that races past the Tree House during heavy rains, park staff dug a large basin to hold the stormwater washing off Northwestern Avenue. The soil proved to have more clay than expected, and instead of the water slowly soaking into the ground, it stayed. To keep the water from becoming too deep, a drainage channel was built, so when the water gets too high, it trickles out and continues on its way to the Wissahickon Creek.

With the basin has come wildlife. Dragonflies, butterflies, ducks, green frogs, honeybees, raccoons, dogs, and toads can be seen using the water in the stormwater basin. Within a year, the food web of this pond kept mosquito larvae in check.

Each year toads return to the pond and for several days in the spring the mating sound of the male American toad can be heard hundreds of yards away. Male toads arrive first to establish their territory and begin to call the females. The trill is unmistakable. Last year we counted at least thirty toads on a warm spring day.

Once paired, the female lays eggs in two spiral lines that look like a phone cord. The eggs hatch about one week later, and the tiny tadpoles mass together eating the pond algae. The warmer the water, the faster they develop. By early June, when the legs are formed, thousands of toadlets leave the pond and begin their journey into the forest. At that point they are the size of a small fingernail–so small and numerous that you need to watch your step to avoid them all!

Once the toads have left the pond, there is still plenty to see. Green frogs lie under the cattails, and Monarch butterflies and black and white dragonflies add a splash of color to the pond. Honeybees from our hives can often be seen taking a drink of water along the edge.

This spring you may see work being done to the pond. The cattails are expanding and soaking up the water too well, and at times in the summer the pond is almost dry. A few cattails will be removed and a deeper pool will be created to increase the water volume and allow frogs and tadpoles a place to go until the next storm. So next time you park your car in that lot, take a peak over the grassy hill, and see what life you can find!

By Trish Fries, Wissahickon Environmental Center. Trish Fries is an Environmental Education Program Specialist at the Wissahickon Environmental Center.