St. Mary’s College Students
Research Wildlife at Gratiot Lake
In July and August, three St. Mary’s College of California seniors, under the guidance of their biology professor, Andrea Nicholas, undertook research projects at the GLC Preserve. The projects were part of St. Mary’s Summer Research Program which engages science students in off-campus hands on scientific study. Brian Rajdl assisted in orienting the students to wildlife sampling techniques and the use of equipment. The group stayed for three weeks at the Noblet Field Station.
The St. Mary’s students’ work has enriched our understanding of Gratiot Lake, and is a welcome addition to our baseline data on the lake and its ecology.
Crayfish were the focus of Mary Heady’s research (photo left). Using baited minnow traps to catch her subjects, Mary identified four crayfish species in the lake: northern crayfish, northern clearwater crayfish, nail polish crayfish, and devil crayfish. We were pleased to learn that the invasive, alien rusty crayfish was not found.
Using a ratio she developed using measurements of crayfish body size and the size of their chelae (large front pincers), Mary developed a hypothesis about which of the native species would be most likely to defend themselves against any future invasion of the rusty crayfish, an aggressive species with large chelae. Mary won an award at St. Mary’s for this research.
Valerie Renosto studied plankton and took lake water samples at various depths using a plankton net. She identified her tiny “catch” under the microscope. Along with the native plankton, Valerie discovered that Gratiot Lake is now home to one potentially troublesome, tiny crustacean, the spiny water flea. It is too early to predict whether spiny water flea will cause problems for Gratiot Lake anglers or fish.
David Schwartz surveyed the diversity of mammals from top predators to herbavores on the GLC Preserve. David used track plates (soot coated aluminum sheets) and raked sandy shoreline to serve as templates to collect animal tracks. He set out live traps to inventory small mammals present. Using pre-recorded animal distress calls he attracted larger predators. A highlight of his project was hearing wolves howl back!
In all, 22 mammal species were detected including black bear, gray wolf, fisher, coyote, beaver, raccoon, white-tailed deer, eastern and least chipmunks, thirteen lined ground squirrels, northern short-tailed shrews, red and gray squirrels, striped skunk, and a variety of voles and mice. David won a prize for his poster which detailed his research.
