Marbled Salamanders

Hi, this is Iain MacLeod from New Hampshire Audubon, bringing you Something Wild.

Most amphibians breed in the spring, but marbled salamanders breed and lay their eggs in September and October. Marbled salamanders are one of several species known as mole salamanders, because, except for the breeding season, they spend nearly all their lives underground.

These secretive animals are nocturnal, and often use small mammal tunnels to get around unseen. They're black, with lighter bands on their back, and are only about four inches long.

So why breed in the fall? Nearly all amphibians breed in water, but adult marbled salamanders can't swim. Their larvae, however, are aquatic, and need water to survive. So in the fall, well after other amphibians have bred and their young have moved onto land, marbled salamanders migrate to the now dried-out vernal pools. They mate, and lay their eggs just before the autumn rains fill the pools again.

Females form nests in moist, protected depressions, somewhere between the deepest and shallowest portions of the pool. This strategy helps prevent eggs from hatching too early, should any late-season thunderstorm temporarily flood the deepest spots, and also ensures that the eggs will be flooded by early winter.

Each female lays 30-100 eggs and will usually stay to protect them, until rains fill the pool and she is forced to leave. When the nest becomes flooded, the eggs hatch, and the larvae begin their lives in the water.

If the winter is mind, the aquatic salamander larvae can develop quickly, and metamorphose into land-dwelling juveniles by early summer. If the nest does not flood in fall, the eggs will go dormant, and then hatch in the spring. These spring-hatch larvae will transform into juveniles by late summer. It takes about one year for the juveniles to become adults.

Marbled salamanders are listed as endangered in New Hampshire, where they only breed in the southwest part of the state.

Something Wild is a joint production of New Hampshire Audubon, New Hampshire Public Radio and Society for the Protection of New Hampshire Forests. For Something Wild, I'm Iain MacLeod.