Record-setting frog sampling

Dates: June 19-21, 2017

Participants— From Colby: Cathy Bevier, Bonje Obua, Corin Balan
From Unity College: Cheryl Frederick, Matt Chatfield, Greg LeClair, Rachel Bidek

Brief Description:

Our focus was to complete “official” sampling of adult male green frogs from three ponds on Allen Island for the amphibian health project. We sampled each frog’s skin using cotton swabs and rinsing to investigate the frog microbiome, skin secretions, and the presence of two frog-specific pathogens. We also are collecting water and sediment samples from the ponds to test for different heavy metals and pesticide residue. The first shift, a crew of four researchers, arrived bright and early Monday morning. Even though it was overcast and foggy for much of the day, we managed to reach a half-way point by evening. The rest of the crew arrived in a blustery downpour Tuesday morning, but “out came the sun and dried up all the rain” by late morning. We achieved our sampling goal by early afternoon while keeping up a rate of about four frogs an hour. Everyone and every critter survived, and the first shift crew departed Tuesday afternoon with all the swabs, tubes, agar plates and sampling gear. Matt, Cheryl, and Rachel stayed behind to complete the water and sediment sampling. As of June 29, we’re also done sampling green frogs in ponds from the Unity and Waterville areas. We’re anxious to dig into the data and results are starting to trickle in.









One potential measure of health we’re quantifying is the amount of yellow coloration male green frogs have developed for the breeding season. As you see in the photographs, this can be quite variable. These two frogs from Allen Island populations are showing off their colors, but one has extensive yellow extending from the vocal sac of his throat, while the other has only pale yellow patches on his vocal sac.  We found the same degree of variation in frogs from the other sites back in central Maine.