Vanishing acts
Look beyond the urban bustle. Boston's ponds, grasses and treetops hide some of the state's dwindling species.
Not far from the constant thrum of trucks and cars, in the shadow of a brick high-rise, lies the last Massachusetts refuge of the freshwater threespine stickleback.
The small, silvery fish dart around a tiny Jamaica Plain pond, a splash of spring-fed water no bigger than a corner basketball court. The stickleback, distinctive for the bony plates that cover its body, is one of the state’s rare species, and its Olmsted Park home is the southern-most US location where the fish is known to live.
The threespine stickleback belongs to the fraternity of rare animals and plants that have, against the odds, managed to cling to life in the most urban environs of the state. Within city limits, pummeled by heavy development and battered by invading species, threatened terns and falcons and salamanders are persevering.
But the numbers of surviving rare species in and near Boston have dwindled in recent years. Although the state’s National Heritage & Endangered Species Program lists 43 rare species in Boston, only 10 have been documented in the past 20 years. Some, like the purple needlegrass and the New Jersey tea inchworm, haven’t been spotted in more than a century.
‘‘Much of it is historic,’’ said Tom French, assistant director of the Massachusetts Division of Fisheries & Wildlife. ‘‘It’s not a surprise, really.’’ The rare species have become even rarer as their natural habitat has disappeared beneath buildings and streets. And in the remaining wild areas, new predators have arrived.
‘‘Even if the landscape has not been built up, there are lots of invasive species that have overwhelmed the native species,’’ said Henry Woolsey, program manager of the endangered species program.
The rare species that have managed to survive often live in protected pockets of wilderness — the grasses at Logan International Airport, or parkland within the city. The common tern and the least tern, both considered species of ‘‘special concern’’ — one notch below ‘‘threatened’’ on the state rare species list —both live in the grasses at Logan.
The process of documenting rare species is imperfect, dependent on someone finding and documenting their existence. It’s hard to prove that a plant or animal has completely disappeared, even if it hasn’t been spotted in years. ‘‘At any given time,’’ Woolsey said, ‘‘we don’t have perfect knowledge that it doesn’t exist.’’
Many plants and animals on the state’s rare species list haven’t been documented in decades, and probably no longer exist. The adder’s-tongue fern was last spotted in Boston, at least officially, in 1884. Hentz’s redbelly tiger beetle hasn’t been seen since 1927. And the golden-winged warbler was last documented in 1877.
In the urban core, more rare species live in Boston than its immediate surroundings. While Boston has 10 entries on the recently seen list, Cambridge has just one, Englemann’s umbrella sedge, a threatened grass spotted near Fresh Pond. In Brookline, 10 plants, insects, and animals hold spots on the state’s rare species list — but none has been documented since 1932, when the golden-winged warbler was seen. Similarly, in Somerville, the most recently sighted rare species was a barn owl in 1973. (Barn owls have been spotted in Boston as recently as 1989.)
Meanwhile, MassWildlife’s National Heritage & Endangered Species Program, charged with protecting the endangered species, has not received state funding since 2004. The program has continued using other sources of money, including voluntary contributions, federal grants, and fees, but has not been able to hire scientists. The state ornithologist job has been open for five years.
A happy exception to the grim news of declining species in the city is the peregrine falcon, which thrives in man-made environments. Eight of the 28 peregrine falcons in Massachusetts live in Boston: one pair each nest atop Marriott’s Custom House tower, the Christian Science Church’s administration building, the Deer Island Sewage Treatment Plant, and the control tower at Logan International Airport. Although the peregrine falcon is still considered endangered in Massachusetts, it has been removed from the federal endangered species list. Cities provide their basic needs: The falcons look for high places to build their nests and ready access to food — flying birds. In Boston, they catch robins and bluebirds as they cross the harbor.
‘‘They are just sucked in by urbanization,’’ French said. ‘‘They’re attracted to it.’’
But humans are not always enamored with the falcons, which can attack during mating season. Some buildings with falcon nests have adapted by changing their maintenance schedule. ‘‘I’ve played umpire between the falcons and people cleaning windows and changing lights,’’ French said.
In Jamaica Plain, the small pond where the freshwater threespine stickleback live is sunken behind a hill in the woods. But it is hardly secluded.
On a recent sunny afternoon, runners padded by on a trail slick with last year’s oak leaves. A yellow Lab bounded down the path, leaped into the pond, splashed around, and leaped out.
A rusted bike rim and a Three Musketeers wrapper have come to rest beside the pond. At the lower end, a brown shoelace drapes across a rock. Two new pennies gleam in the water.
But the threespine sticklebacks persevere. Karsten E. Hartel, curatorial associate in ichthyology at the Museum of Comparative Zoology at Harvard University, first saw them in the 1950s, when he was growing up in Jamaica Plain.
‘‘As kids, we always knew that they had sticklebacks in the pond,’’ he said. Hartel later documented them in his 2002 book, ‘‘Inland Fishes of Massachusetts.’’ An ice-skating rink once stood near the pond, and some environmentalists worried that its run-off would pollute the pond. The rink was later torn down, and now a meadow grows there. French is more optimistic about the long-term prognosis of the sticklebacks than about other rare species found within city limits.
‘‘It’s probably secure, or reasonably secure, because its habitat is protected in the Emerald Necklace,’’ French said.
More rare species than we know may exist in Boston and nearby communities. Last summer, after a stressful meeting in Boston, French was driving home when he stopped for a breath of air in a parking lot beside the Charles River. As he walked along the shore, he stumbled across the shell of a rare freshwater mussel, the triangle floater — which doesn’t appear on the list of threatened species seen in Boston.
‘‘If we haven’t found that in one of the closest city parks in the river,’’ he said, ‘‘then there are still things to be found.’’
Kathleen Burge can be reached at kburge@globe.com
