The old adage that April showers bring May flowers remains true, even as the planet warms and the timing of many events in the natural world shifts one way or the other. But what is equally true is that March showers bring frogs and salamanders. So we should pay close attention as we drive dark roadways during evening rains this month, because those amphibians will be on their way to and from their breeding ponds, which often means crossing roads. It would be a shame if our vehicles bring their annual migrations to a violent end just before the creatures complete their mission.
Several species of frogs and salamanders that are crossing roads this month have the remarkable ability to hibernate among the leaf litter and in shallow burrows during the winter, at which time most of the water in their body turns to ice. And yet as temperatures warm, they unfreeze and go about their regular activities. They can do this thanks to their ability to produce a concentrated sugar solution that acts like anti-freeze to prevent damage to sensitive organs. This anti-freeze is triggered when their body temperature falls and their metabolism drops. Sometimes their hearts even stop beating.
Wood frogs and spring peepers – both small, tan colored animals – are perfect examples. They are best known as the loud-mouthed frogs that congregate in vernal pools and small ponds in March and April as they seek mates and lay eggs. They are often joined by spotted salamanders, which are attractively dressed in shiny black with bright yellow spots. But getting to their breeding ponds is often a dangerous trek, and many don’t make it.
Compared to birds, many of which may travel thousands of miles to the Tropics and back each year, the migration of local frogs and salamanders is nothing to brag about. A 2005 study by researchers at the University of Rhode Island found that most spotted salamanders only travel about 150 meters from their wintering site to their breeding pond. Yet because of the fragmentation of their habitat by roads and houses, it’s often a trip fraught with danger.
Their migration typically occurs during nighttime rain storms as the weather warms in mid- to late March, though it got an early start this year due to our unseasonably warm February. (Cold winters like last year – when many breeding ponds were still frozen until April – can delay the trip for several weeks.) If you drive dark roads near wetlands at this time, your headlights will likely illuminate frogs hopping across the road. Please be careful.
Last April during a warm evening rain shower, I walked a one-mile stretch of road adjacent to a series of ponds near my house, and with flashlight in hand, I found more than 50 wood frogs and spring peepers attempting to cross the road. I escorted each one to safety in the direction they were facing. It’s a good deed that youth groups and other interested parties engage in frequently during this season. And you can, too.
If you want to get even more involved in studying and protecting our local frogs, become a Frog Watch volunteer and monitor amphibian calls at nearby ponds. The national citizen science project is managed locally by Roger Williams Park Zoo.
Most important, however, please drive slowly and carefully during evening showers for the next few weeks to avoid migrating amphibians. Thousands of frogs and salamanders will thank you for it.
This article first appeared in The Independent on March 17, 2016.