Why Do Ambies Cross the Roads?

The reasons that ambies cross roads “en masse”, are to mate and lay their eggs in vernal pools (which are pools of water that dry up in the summer and are refilled each spring). These amphibians have evolved to spawn in vernal pools simply because in most regular ponds fish will eat their eggs (and fish cannot live in vernal pools, since they dry up).

There have been few studies of salamander roadkill rate, although anyone living near a crossing site has probably seen dozens of flattened salamanders “the morning after.” Last year in Middlesex alone, volunteers patrolling for salamander activity on April 13th moved a total of about 125 salamanders across the roads. And even with extensive human help, about 25 salamander fatalities (17%) were counted.

In one 1990 report, it was calculated that if traffic density exceeds 26 cars an hour, from 50 up to 100 percent of migrating amphibians may be killed when crossing. Unfortunately, since these are burrowing animals and very light-sensitive, they are apt to freeze when in car headlights, making them less likely to survive a road crossing.

Nobody wants to kill a beautiful salamander on purpose, but they are difficult to recognize in the road. However, knowing what to look for, when to look for them (the majority cross in just one night a year) and where (only three main spots in the geographically-large town of Middlesex, for example) makes it much easier to avoid running them over.

How to avoid flattening ambies: click here.

A Few Reseach Articles on Roadkill and Amphibians