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On slippery ground: Salamanders brave dangerous crossing to pursue rites of spring

The Binghamton University Nature Preserve supports a relatively stable population of spotted salamanders, which each spring migrate from the woods, where they winter in small mammal burrows and tunnels, to a breeding ground like Harpur Pond or the pond at Nuthatch Hollow Nature Preserve.

If everything is perfect — temperature in the 50s, a gentle misty rain and the timing in sync with their internal clocks — the salamanders will cross the road en masse and head straight for the ponds on one specific night. But if that enchanted evening comes too early or too late in the season, the salamander migration is drawn out over a period as long as two or three weeks. An informal network of observers keeps watch during the early spring and relays information about the year’s migration to biology professor Dale Madison, who has done extensive research on this particular creature, Ambystoma maculatum.

When the spotted salamanders migrate en masse, “it’s kind of exciting,” said Madison. “You see a lot of very precious creatures in your lamplight and feel good that you can help them on their journey.” Madison and the other observers facilitate the salamanders’ safe and successful crossing, either by guiding them to special asphalt ramps built specifically to facilitate their safe migration, or by gently picking them up and setting them down on the pond side of the road.

“The curbed road acts as a dry moat,” he explained. “They’re not very maneuverable creatures, so they fall down one side and bump into the wall on the far side.” Before the salamander ramps were built in 1978, the amphibians became trapped in the roadway, where many died of dehydration, were eaten by crows and other predators, or were killed by traffic.

Once Madison is assured the annual crossing is over, he makes a call and gives the all-clear to Physical Facilities. Then, and only then, does the University reopen the road, which is closed throughout the winter. This year, Madison gave the go-ahead to reopen the access road on Monday, April 8.

Under-cover insect control

One of many creatures that make up the ecological balance in the Nature Preserve, the spotted salamander eats insects and worms and consequently acts as a check on insect abundance. People rarely see these amphibians at all, because they remain still and hidden under the leaf litter throughout the summer, where they patiently wait for unsuspecting meals to crawl by. Spotted salamanders are also called mole salamanders, because of their choice of winter abodes, which are often mole tunnels, Madison said.

The salamanders’ return trip in the fall is much less synchronous than their spring migration, Madison said. He knows, because he’s actually put mini-radio transmitters in them. “Some will make movements out of the pond right away. Others wait to the end of the summer to make the return trip,” he said.

Another discovery Madison made in tracking salamanders’ movements is that the older spotted salamanders seem to abdicate the best feeding and breeding grounds to younger generations, risking their own lives in dangerous migrations to territories further away from the pond.

Diminishing numbers

The population of the spotted salamander is diminishing in New York state, and that’s one reason why they’re of special concern, said Madison. They can live 18 or more years, and they don’t replace themselves that readily. Although he doesn’t have hard figures, Madison believes that the population of spotted salamanders in the Nature Preserve is lower now than it was 15 years ago, partly because of the traffic and partly due to the beavers in the pond. “Beavers tend to modify the habitat and make it less suitable for salamanders,” said Madison.

“When people go out on wet evenings in early spring to jog or walk on the access road, that’s when they can do the most damage,” Madison said. So, tread cautiously on the roads in or near the woods on misty spring evenings. It’s a time that’s crucial to the survival of spotted salamanders, as it is to many creatures of the woods.

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