April showers bring spring amphibians. Watch out for salamanders and frogs crossing the road on warm, rainy nights.
The most impressive movement of local amphibians is the spring migration of Jefferson, blue-spotted, and spotted salamanders, three relatively large-bodied species which spend most of their adult life in dry forests but must lay their soft eggs in woodland ponds. Thousands can come to a pond in a single night, and cars can kill a significant number if their route crosses a road.
A mass emergence usually happens during the first really warm, heavy rain of spring which thaws the ground to the level where the salamanders spent the winter, said Todd Bittner, the Director of Natural Areas at Cornell Plantations. The timing varies throughout Tompkins County due to elevation and other factors. This year, Bittner said that dribs and drabs of rain led to a more staggered emergence.
Most local salamanders have already reached their ponds this year, according to Brian Worthington, President of the Cornell Herpetological Society, although there are always stragglers. Males set up little areas where they court females by dancing. Soon the adults move back to the woods, leaving egg masses behind. The salamander larvae that hatch are very similar to tadpoles except they have large, feathery gills and never lose their tail.
The coordinated movement of so many salamanders may overwhelm their predators, which include raccoons, birds, and feral cats, said Worthington. It also provides a focus for human intervention. Some areas have official Salamander Crossing Brigades, such as those organized by the Ashuelot Valley Environmental Observatory in New Hampshire, which manually move salamanders across dangerous roads. Local efforts are more decentralized. According to the society’s faculty advisor, Kraig Adler, “The Cornell Herpetological Society informally supervises the amphibian migrations at Bull Pasture Pond on the Cornell Golf Course because the number of community members and Cornell students who wander across the breeding migration corridors is quite large.”
Leann Kanda, a biology professor at Ithaca College, has helped John Confer organize volunteers to escort spotted salamanders across Thomas Road in Ellis Hollow since 2007. “The last couple of years we have had amazing turnout,” said Kanda, with as many as 30 volunteers in one night. Because they record each species encountered and its fate, Kanda can demonstrate that 10 to 20 percent of the salamanders are still killed by traffic during their active intervention. Spotted salamanders can live 15 to 20 years in the wild and researchers do not know the long term effects of these deaths on salamander populations. Kanda is currently monitoring individual salamanders to better understand their population dynamics.
Culverts may be part of the solution at nearby Ellis Hollow Road. Bittner would like researchers to collect data on a culvert system installed over a decade ago by Cornell Plantations at Ringwood Ponds Natural Area. Bittner called Ringwood Ponds the most significant herpetological site in Tompkins County because its rich, complex geology, which includes at least a dozen ponds, creates diverse habitats and fosters diverse amphibian populations. Unfortunately, a county highway bisects some of the areas where salamanders and newts like to overwinter and runs close to the most well-known pond. “The idea was to try to funnel the salamanders and newts along the plastic drift fence and then under a culvert that ran under the road,” Bittner said.
Most amphibians appear to safely cross Ringwood Road through the tunnel, based on his casual observations, but many still end up on the road. Because Bittner lives nearby, he and his family often spend time during migration helping amphibians cross. “You feel good about it,” Bittner said. “You get them where they want to be.” It is an opportunity to interact with species which otherwise live underground or, like spring peepers, are easy to hear but hard to see.
Bittner encounters other groups of helpers such as the Cornell Herpetological Society. Sometimes individual good Samaritans will pull their car over, help an amphibian across, and then drive away. People looking to help on their own should be watchful of traffic and always handle amphibians with wet hands free of lotions, bug spray, or other chemicals that can harm them through their delicate skin.
If you do go looking for salamanders in their woodland ponds, remember that some of these sites are sensitive and access may be restricted. Follow any site rules. Be watchful for amphibians on the road or under foot. Visitors might also see or hear wood frogs, pickerel frogs, and spring peepers.