April 19, 2005 > Animal tracks
by Arathi Satish
Walking across the beach, you can look back and see footprints in the sand. These tracks show which way you were going, what you were wearing on your feet and how fast you were moving. The same is true for animal tracks that tell the story of what type of animal passed by and where it was headed.
Some tracks can be very old like dinosaurs, preserved in rock; others can be fresh prints made by a deer that passed by a few hours ago. Learning how to read animal tracks is a science practiced by biologists and naturalists. Ask any student at John Gomes Elementary School who attended the Animal Tracking Workshop to identify the tracks of opossums, rabbits, coyotes, deer, mountain lions and raccoons, and they can tell you all about them.
At Gomes Elementary School, teacher Rosemary Cortez with the assistance of parent volunteers, helped students make plaster of Paris impressions of animal tracks. They learned about the size, shape and distance between the prints, not only revealing the identity of the animal, but also its gait or stride pattern. Cortez talked about tracks found on the ground, trees, in underground burrows and snow.
The children engaged in hands-on experience with tracks. Parents filled disposable bowls with a mixture of sand and water, so that a print left by an animal would be clearly outlined. Next, they pressed casts of various animals' footprints into the sand until a clear imprint was obtained then visited a workstation in groups of five and mixed plaster of Paris and water in disposable plastic cups, stirring until it looked like a milkshake. Plaster was then poured over the footprint. Slowly it hardened and, after 45 minutes, was gently separated from the sand as students excitedly gathered to view their creations.
Cortez taught the children (and their parents) how to identify various tracks and the critters that made them. The first step in track identification is pinpointing the family of the animal by the mark of the toes, heel pads, hooves or other distinguishing marks. Canine and feline track prints show four toes on the front and rear feet. Rodent tracks show four front toes and five rear toes in a fan-like pattern. Hoofed animals, like deer and elk, produce a "two-toed" track. In addition to the shape of the foot, the track pattern is an important indicator of the type of animal that made those marks.
A field guide helps identify prints by comparing and indexing track shape, imprint distance and stride length. Cats, dogs, and hoofed animals are called diagonal walkers, meaning that one of the front feet moves forward in conjunction with the opposite rear foot. Wide-bodied animals such as raccoons, opossums, and beavers are called pacers, producing a waddling gate in which the left front track print is generally directly next to the right rear print. Mud, sand, dust, and snow are surfaces on which it is likely to find impressions left by animal footprints.
Visitors to Gomes Elementary school may find students intently studying unpaved areas around their school. A conversation with these outdoor sleuths may yield a wealth of information about a menagerie of animal visitors that have also made use of the Gomes grounds. Do you know who shares your yard?