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Amphibian Migrations and Road Crossings

In 2018, volunteers counted more than 2,800 amphibians and helped at least 1,771 across roads during the migration. Read the AM&RC 2018 Project Summary (PDF 1.57 MB).
Watch a short video about amphibian migrations and check out other videos on DEC's YouTube channel.

Why did the salamander cross the road?

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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, 950 KB) are important links in forest food webs and indicators of healthy, functioning ecosystems.

A volunteer holding a salamander
Over 200 volunteers have helped thousands
of amphibians cross roads to safety during
spring migrations in the Hudson Valley.
(A. Bloomfield)

Seasonal Migrations and Road Mortality

While they spend much of the year in their terrestrial habitats, mole salamanders and wood frogs all breed in woodland pools, a type of small, temporary wetland found in forests. During early spring rains when temperatures rise above freezing, these amphibians migrate to breeding pools by the hundreds, if not thousands. The marbled salamander is different from the other species in this group, as it breeds in the fall.

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, migration pathways often cross roads and long driveways, leading to mortality of slow-moving wildlife, even in low traffic areas. Fragmentation of forest habitats and loss of wetlands also contribute to declines in amphibian populations in the region.

How can you help?

The Hudson River Estuary Program and Cornell University Department of Natural Resources are working together to conserve forests, woodland pools and the wildlife that depend on these critical habitats. You can help by telling us when and where you see migrations of woodland pool amphibians. 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 breeding season. Eventually, we can also learn whether the timing of spring migrations is shifting due to climate change.

Documenting "Big Nights"

close up of a wood frog on dark pavement at night with a spolight illuminating the frog
Wood frog during spring migration (L. Heady)

Spotted, blue-spotted and Jefferson salamanders and wood frogs emerge from hibernation on rainy nights in early spring, usually March or April, when the ground is thawed and air temperatures reach 40ºF. (Marbled salamanders breed 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." To submit your observations of woodland amphibian migrations and road crossings, fill out and submit the data collection form (PDF, 528 KB).

We're interested in learning about both the timing and conditions of migration events, as well as road crossings where animals are especially vulnerable. If you are in a hurry, the most important sections to complete are your name, contact information, date, time, temperature, conditions, and details about the road crossing. If you have enough time and know a little (or a lot!) about amphibians, collect information about the species and numbers you observe. Take photos if you have a camera. Watch your step; there may be salamanders and frogs underfoot!

Completed data forms and photos should be submitted to:

Woodland Pool Project
NYSDEC Hudson River Estuary Program
21 South Putt Corners Road
New Paltz, NY 12561
fax: (845) 256-3649

Finding New Crossings

You can also search for new crossings through your windshield. To conduct "road surveys," you should bring a partner and drive slowly (10-15 mph) in areas with appropriate habitat (the driver must pay attention to the road and traffic, while the spotter looks and listens). When you find an area where there are signs (amphibians moving across the road or road-kill), carefully park the car in a safe location, avoiding animals as well as traffic. Follow the directions on the data form (PDF 528 KB) to record your findings.

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 go out, brush up on amphibian ID with color brochures from the New York State Department of Environmental Conservation:

The Amphibian Migrations and Road Crossings project is part of a larger Hudson River Estuary Program biodiversity 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
21 South Putt Corners Rd.
New Paltz, NY 12561

Volunteers counted more than 2,800 amphibians in 2018 and helped at least 1,771 across roads during the migration. Read the AM&RC 2018 Project Summary here.