Department of Environmental Conservation

D E C banner

Amphibian Migrations and Road Crossings

Watch a short video about amphibian migrations. Check out other clips on DEC's YouTube Channel.

Why did the salamander cross the road?

Sign up for DEC Delivers

Enter email address:

Have you ever witnessed large numbers of salamanders and frogs crossing the road on rainy spring nights? Ever wonder where they came from and where they're going?

Mole Salamanders and Wood Frogs

An adult spotted salamander in someone's hands.
Many amphibian species, like this spotted salamander, need
healthy forests and wetland complexes throughout the estuary
watershed. (L. Heady)

The forests of New York are inhabited by a group of salamanders that are seldom seen, as they spend much of their time under leaves and moss on the forest floor, in burrows created by small animals and hunkered down under rocks and rotting logs. Referred to as "mole salamanders" because of their subterranean shelters, this group belongs to the family Ambystomatidae and, in the Hudson Valley, includes the spotted salamander (Ambystoma maculatum), the Jefferson salamander (A. jeffersonianum), the blue-spotted salamander (A. laterale) and the marbled salamander (A. opacum). The mole salamanders forage on the forest floor for a variety of invertebrates, including earthworms, snails and insects. Another small amphibian you may see while walking in the forest is the wood frog (Rana sylvatica). Mole salamanders and wood frogs (PDF) are important links in forest food webs and indicators of healthy, functioning ecosystems.

Seasonal Migrations and Road Mortality

two volunteers in safety vests assist a salamander to cross a road safely in the Hudson valley at night
More than 370 volunteers have helped
thousands of amphibians cross roads safely
during migrations in the Hudson Valley.
(L.Heady)

While they spend much of the year on land, mole salamanders and wood frogs all breed in woodland pools, a type of small, temporary wetland found in forests. Spotted salamander, Jefferson-blue spotted salamander complex, and wood frogs emerge from hibernation on rainy nights in late winter and early spring, usually in mid-March to early April, when the ground is thawed and evening air temperatures stay above 40ºF. (The marbled salamander is different from the other species in this group, as it breeds in the fall.)

When conditions are right, there are often hundreds, if not thousands, of amphibians on the move; amongst nature enthusiasts, these spring migration events are often referred to as "Big Nights."

But why are these amphibians so frequently seen crossing the road? Migration distances to woodland pools can vary from a few hundred feet to more than a quarter of a mile. Unfortunately, because forest and wetland habitats are often disconnected by development, many migrating amphibians need to cross roads and long driveways, leading to mortality of slow-moving wildlife, even in low traffic areas.

How can you help?

The Hudson River Estuary Program and Cornell University Department of Natural Resources are working with communities to conserve forests, woodland pools and the wildlife that depend on these critical habitats. You can help by participating in the Amphibian Migrations and Road Crossings Project. The Volunteer Handbook (PDF) provides detailed instructions, including safety measures, proper handling of amphibians, and data collection. Volunteers record their observations on the project data form (PDF) and can submit their data online (link leaves DEC website), or mail or email a copy of the form, if preferred.

Since the project started in 2009, more than 370 volunteers have counted at least 20,000 amphibians and observed 20 species. They assisted 12,000 amphibians across roads during migrations and counted more than 5,700 migrating amphibians killed by passing vehicles.

Resources for Volunteers

Volunteers are encouraged to sign up to receive migration alerts and updates by subscribing in the blue "DEC Delivers" box above. Most email correspondence from this list is limited to February through April.

Your observations will enable us to identify and map road crossings where mole salamanders and wood frogs are especially vulnerable and learn more about where their habitats are located. This information can then be used for community planning and for groups of volunteers interested in starting "crossing guard" programs for the amphibian breeding season. Eventually, we can also learn whether the timing of spring migrations is shifting due to climate change.

Amphibian Identification

A fertile hybrid of a Jefferson and blue-spotted salamander
Jefferson's salamander and blue-spotted salamander interbreed
and the fertile hybrids are difficult to distinguish from their parents.
(L. Heady)

Before you head out for the migration, brush up on amphibian ID with guides from DEC:

The Amphibian Migrations and Road Crossings project is part of a larger Hudson River Estuary Program initiative to partner with local communities to conserve the diversity of plants, animals, and habitats that sustain the health and resiliency of the entire estuary watershed. For more information, contact:

Laura Heady
Hudson River Estuary Program's Conservation and Land Use Program Coordinator
NYSDEC
21 South Putt Corners Rd.
New Paltz, NY 12561
email: woodlandpool@dec.ny.gov