Cornell Botanic Gardens, the college arboretum in Ithaca, New York, manages Ringwood Preserve, which features spring peepers, red-spotted newts, wood frogs, spotted and Jefferson salamanders, turtles and, of course, toads. The road through it, which separates the preserve from a breeding pond, carries about 600 vehicles a day, creating close encounters of the not-so-good kind between amphibians and cars.
Millions of amphibians throughout the northeast (already in precipitous decline for a variety of reasons) are killed each spring, as they migrate across roads on warm, rainy nights to their breeding ponds. “As conservation-minded herpetologists, we wanted to reduce this slaughter,” says Jacqualine Grant, a Cornell graduate student.
Grant envisioned a “drift fence” to help guide amphibians to an already existing culvert underneath the road, and helped raise $5,000 for it. The fence, created for this purpose by a polymer company, is made from recycled plastic, and curves over on top to prevent hopping creatures from straying.
In one long workday, the group successfully installed the “toad tunnel” in an area previously surveyed for mortality. “One evening I counted over 100 road-killed newts there,” notes Grant. “Over the course of a breeding season, we will have saved hundreds of animals.”
Such “critter crossings” are found nationwide. Each spring, migrating salamanders in Amherst, Massachusetts use similar tunnels to reach breeding pools. The town has even posted a “Watch Out for Salamanders” sign to slow down motorists. University of Massachusetts amphibian expert Scott Jackson, who helped design the tunnels, offers tips to would-be protectors that include: Design tunnels to accommodate site conditions; avoid single-species designs; know the biology of the target species; locate tunnels close to the species” movement corridors; monitor the project and share the results.
A state Department of Transportation design team followed these recommendations when planning a culvert across a stream in Pawtucket, Rhode Island’s historic Slater Mill Park. They added shelves inside the culvert, slightly above the water. Now green frogs, mice and other wildlife can continue their path alongside the stream. Since the shelves were added before construction, they added little to the cost.
It’s in our own best interest to protect amphibians, adds Grant. They eat vast quantities of mosquitoes and flies. And what would springtime be without the cheerful calls of spring peepers?