Sometimes they don't come out of their shells
Less than a mile from Northampton Community College's Main Campus in Bethlehem, the appropriately named "Green Pond" occasionally spills across the winding road that leads to campus.
The marshes around the pond are a popular destination for bird watchers. Some say 160 different species of birds have been spotted there. What other creatures make their home in and near the pond?
Ask NCC ecology students. This fall Karen Klein's general ecology and field ecology classes helped with a "mark-recapture study" to estimate the number of different species of turtles in the pond. According to Klein, because scientists can't count each and every animal in a habitat, they use mark-recapture studies and a "Lincoln Peterson estimate" to calculate the size of the population.
To capture turtles, the students set hoop funnel traps in the pond, baited them with sardines and vegetables, and then checked them 24 hours later. Some days the traps were empty. On other days, students carefully removed the turtles from the traps and measured the length of their shells, the size of their front claws, their weight and the general state of their health. Eastern painted turtles and Red-eared slider turtles were marked with a harmless scute notch technique so they would not be double-counted if they were recaptured later. Snapping turtles were not marked due to their aggressive nature. All of the turtles were released back into the pond.
See the students at work and meet some of our reptilian neighbors in this Flickr gallery.