Tuning in to squirrels
A Bell Museum educator holds a tall antenna and cigar-box-sized receiver (on his belt), while several elementary school children try to pinpoint a squirrel's location.
Playing hide and seek with the squirrels
By Jennifer Amie
Published on June 20, 2005
The gray squirrel population in the Bell Museum of Natural History's neighborhood boasts a number of oddities; namely, a bevy of albinos and a pair equipped with antennas. The latter, known as No. 701 and No. 742, sport watchband-like collars that sprout four-inch-long flexible wires. The garb is part of a radio telemetry-tracking device, and the squirrels are (seemingly oblivious) participants in a scientific experiment designed by University of Minnesota faculty and Bell Museum education staff and executed entirely by elementary and middle school students from the Twin Cities area.
Dubbed "The Secret Lives of Squirrels," the program is now in its pilot phase and will be launched in its entirety this summer. Its aim, says museum educator Christopher Goodwin, is to give children a chance to participate in real science--from learning how to formulate a research question and devise an experiment to collecting and analyzing data.
The program kicked off in September 2004 when Goodwin and University professor James David Smith set out wire traps baited with oatmeal and peanut butter to attract a pair of subjects. Within 30 minutes they had "recruited" two squirrels, a male and a female, who were briefly treated with an ether-like anesthetic while their radio collars were attached. "Each collar [which is equipped with a tiny, battery-operated transmitter] has its own frequency and is like a miniature radio station that transmits a 'beep, beep, beep' rather than news or Top 40," says Goodwin. The range of each transmitter is 10 miles.
Using a tall antenna and a receiver the size of a cigar box, school groups and summer campers can track the squirrels and record their whereabouts. Recently, a group of children was hot on the trail of No. 701, taking turns to hold the antenna and listen to the "beeps" on headphones.
U invention: radio
John Tester, Dwain Warner, and Larry Kuechle developed radio telemetry--a way to measure a quantity and transmit the result to a distant station--at the University of Minnesota about 50 years ago. They tested the technology on foxes, raccoons, skunks, ruffed grouse, and owls at the U's Cedar Creek Natural History Area. Since its invention, radio telemetry has been used all over the world in animal studies. "We can outfit the largest elephant or the smallest songbird," says Kuechle, who now owns a telemetry equipment manufacturing business in Isanti, Minnesota. "[And] we can build a transmitter that weighs no more than six tenths of a gram."
Once a squirrel is spotted, its location is marked on an aerial photograph of the Bell museum grounds and nearby buildings. The coordinates are entered into a computer database that tracks the squirrels' locations over time (in various seasons and under different weather conditions) and at different times of the day. Cumulatively, the data can be used to generate maps of the squirrels' territories.
The students can then pose and test research questions, such as whether male or female squirrels have larger territories or whether the size of territories varies depending on weather, temperature, or season. "[Thus far,] we're finding that their territories are about twice the size of the Bell Museum grounds," says Goodwin.
He adds that in a couple of years, when the territorial boundaries for different squirrels are established, the student scientists could start to look at the squirrels' feeding habits. One possible experiment, he offers, might be to install a feeder in one squirrel's territory and then to observe whether that new food source causes other squirrels to invade its territory.
The mapping software used to record and analyze the tracking data was developed in the University's College of Natural Resources, and the technology used in this program--radio telemetry--was invented by Bell Museum scientists John Tester, Dwain Warner, and Larry Kuechle in the late 1950s and early 1960s.
Although today's scientists have used radio telemetry to study everything from tigers to salmon, there is little, if any, research related to gray squirrels. Squirrels, however, make an ideal subject for an educational program because they are readily available and tend not to stray too far, which makes them easy to track on foot. "Urban kids are familiar with squirrels," says Goodwin. "This project can give them a sense that science happens everywhere, not just in wild or exotic places."