A childhood trip to the rainforests of Costa Rica introduced Taegan McMahon '07 to poison dart frogs. Immediately, she was smitten. “They are very cool and absolutely beautiful,” she says.

Back home to Noank, Conn., McMahon raised them as pets. By sophomore year at Bates, she knew the inch-and-a-half amphibian would be a big part of her biology senior thesis.

Advised by Assistant Professor of Biology Ryan Bavis, she investigated how acid rain — a relatively new rainforest phenomenon — might affect the growth of the dart-frog species Epipedobates tricolor.

"Global amphibian decline is well documented," McMahon says, "as is the negative effect of habitat acidification on amphibians." Measuring that effect on a specific species was McMahon's goal.

Her experiment had some E. tricolor  tadpoles living in slightly acidic water (pH 6.0) and others in neutral water (pH 7.0).  Over the winter, she compared their health and growth. At the Mount David Summit in March, McMahon announced her results. Tadpoles trying to grow in acid rain-like water were stunted or deformed. Many died.

"This study shows that Epipedobates tricolor is particularly sensitive to acidification," she concluded.

As graduation loomed, McMahon and her adviser prepared to submit the research to a peer-reviewed journal. Her post-Bates plans, meanwhile, reflect diverse interests. A research internship will take her to Corcovado National Park in Costa Rica, while another internship will be in a fabric design studio. "Distinctly different," says the typically upbeat McMahon. "But I'll love them both!"

Read more about Taegan McMahon '07 in Bates Magazine.