Amphibian Migrations and Road Crossings
Need to refresh your identification skills? Check out our Amphibian Identification Guide! It contains photos and descriptions of the frogs, toads, and salamanders that are most frequently encountered in the Hudson Valley during spring migrations to woodland pools.
Why did the salamander cross the road?
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?
During their spring migrations, many amphibians face
dangerous road crossings to reach breeding pools. (L. Heady)
Mole Salamanders and Wood Frogs
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.
Over 150 volunteers have helped thousands
of amphibians cross roads to safety during
spring migrations in the Hudson Valley.
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 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 its migration occurs 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 are both contributing to declines in amphibian populations in the region.
How can you help?
The Hudson River Estuary Program and the 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 salamanders and 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. Over time, we can also learn whether the period of spring migrations may be shifting due to climate change.
- Read more about woodland pool habitat and conservation.
- Download the Amphibian Migrations and Road Crossings Fact Sheet (PDF, 730 KB)
- Download the Amphibian Migrations and Road Crossings Data Form (PDF, 656 KB) to record and submit your observations.
- Download the Woodland Pool Wildlife Photo Identification Guide (PDF, 950 KB)
Documenting "Big Nights"
Wood frog during spring migration
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, 656 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!
Many amphibian species, like this spotted salamander,
need healthy forests and wetland complexes throughout
the estuary watershed. (L. Heady)
Completed data forms (PDF, 656 KB) and photos should be submitted by April 30 to:
Woodland Pool Project
NYSDEC Hudson River Estuary Program
21 South Putt Corners Road
New Paltz, NY 12561
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, 656 KB) to record your findings.
Before you go out, brush up on amphibian ID with color brochures from the New York State Department of Environmental Conservation:
- Woodland Pool Wildlife (PDF) (950 KB)
- Woodland & Vernal Pool Salamanders of NY State (PDF) (410 KB)
- Frogs & Toads of NY State (PDF) (850 KB)
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:
Hudson River Estuary Program's Biodiversity Outreach Coordinator
21 South Putt Corners Rd.
New Paltz, NY 12561
phone (845) 256-3061