The tunnel of love: Keeping salamanders off the streets

PEG HANLEY
Public Information Manager

Mating season for eastern tiger salamanders and spotted salamanders at Battelle Darby Creek Metro Park can get a bit dicey as these determined creatures surface from their underground burrows and march en masse, by the hundreds, across the roadways to vernal pools to mate and lay eggs.

Road crossing mortality is high for salamanders as they move quite slowly on their stubby little legs. Their breeding success can be variable depending on the success of this migration. They are sometimes joined by other vernal pool breeders like frogs and spring peepers. Migration usually occurs during the first warm seasonal rains, in late February or early March, after dark and with temperatures of 40 degrees Fahrenheit or above.

To protect migrating amphibians from squishy deaths and reduce the effects of road mortality by cars, Metro Parks built two experimental tunnels across the road into the nature center. Tunnels are less expensive than going over the road. Since salamanders don’t like dark enclosed spaces where they cannot see the other end, staff came up with overhead grates to let in some natural light. The grates are strong enough to withstand the weight of vehicles. Exclusion fencing was put at the end of each tunnel to help funnel the amphibians into the trenches.

If the project is successful, we hope to work with other agencies to put tunnels across Battelle Darby Creek Drive. Hopefully, the 2021 breeding season will prove to be a light at the end of the tunnel for the eastern tiger salamander and other creatures as they make their annual trek to their seasonal breeding pools.