RANDOLPH — Jacob Kubel is a man on a mission. The 36-year-old conservation scientist with the Massachusetts Division of Fisheries and Wildlife’s Natural Heritage and Endangered Species Program has been crisscrossing the state since late August in search of the Commonwealth’s rarest salamander — Ambystoma opacum, also known as the marbled salamander — to document where it is breeding and to get a feel for how the population is doing. And he only has a couple more weeks to do so before the salamanders head back underground.
“I feel like I can’t stop searching for these guys while I have a hot hand,” Kubel said recently, about his luck thus far in finding the elusive amphibians. With the help of others — including personnel from the Division of Fisheries and Wildlife and the state Department of Conservation and Recreation, as well as academic institutions, land trusts, other nongovernmental organizations, and biologists in the private sector, he has documented marbled salamanders from Bolton to New Bedford, Attleboro to Berlin, and several places in between.
Kubel has surveyed 62 wetlands and found 18 marbled salamanders distributed among 13 wetlands in nine cities and towns this season. He said other biologists have found five. But there is not enough data to estimate how many salamanders are in each local population.
Statewide, Kubel said there are records of approximately 83 local populations, occurring in 78 of the state’s 351 towns, that have been observed in the past 25 years.
Marbled salamanders are unusual because they are fall breeders. In the springtime, vernal pools — temporary small ponds that form from spring rains and melting winter snow — are alive with an assortment of mating frogs, toads, and salamanders. By late summer these ephemeral woodland pools lie empty and devoid of most animal life, save for a few insects and other invertebrates. That is when the marbled salamander — in contrast to its spring-breeding counterparts — makes its way to these dried-out depressions to mate and lay eggs.
But finding the stocky-bodied 4-inch-long creatures can be a bit like finding the proverbial needle in a haystack. Kubel and fellow biologist Tim Beaulieu recently set out to search for them in the Blue Hills Reservation, a 7,000-acre state park just south of Boston.
“We’ve been tending to find one salamander per pool this year,” Kubel said. “If we find a marbled salamander, we say we found it, as opposed to saying we found one.”
In the Randolph section of the park, Kubel and Beaulieu headed down a trail through woods that led to vernal pools where the amphibians had been documented in the past.
“This looks like a good spot,” Kubel said, pointing to a large depression with a muddy bottom and scattered clumps of grass, shrubs, and fallen leaves. “There’s got to be marbled salamanders in here.”
He said the primary purpose of the survey in the Blue Hills, and across the state, is to confirm the continued presence of the species at previously known locations and to learn more about the possible distribution of marbled salamanders and their breeding sites.
“Do you have your search image?” he asked Beaulieu. “They’re black and white, so they’re pretty easy to spot if you uncover one.”
That distinctive black-and-white color pattern is what gives the marbled salamander its name. Males and females have similar markings, but males are brighter than females, a phenomenon that scientists refer to as sexual dichromatism.
“They’re interesting animals,” said Kubel. “They live underground about 10 months of the year, so they’re kind of mysterious, and there’s only a limited opportunity to see them.”
In fact, Kubel said his initial interest in herps — reptiles and amphibians — in general, and salamanders in particular, sprang from their secretive nature.
“It’s like a big treasure hunt,” he said. “I liked the satisfaction of putting effort into searching, and then finding something. Herps are elusive, so it makes you want to learn about them.”
Recent marbled salamander discoveries in Massachusetts have all been in communities south and west of Boston. Kubel said there are a number of historic records of the species north of Boston, most in the late 1800s and early 1900s, with the most recently confirmed record from 1932 in Malden.
“In most cases, the habitat is now gone,” he said, “so the populations are presumed to have been extirpated. Some people are still hopeful they remain at Middlesex Fells [a conservation area that straddles Medford, Malden, Melrose, Stoneham, and Winchester], but surveys to date have been unsuccessful there.”Continued...