Nature Notes: The Not-So-Great Divide

All of a sudden after a worldwide record warm year in 2014, the winter turns frigid. Noyac Bay is half frozen, all of the freshwaters are iced up, the ground is still covered with a couple of feet of snow, and the land and water birds are having a hard time of it. These are the times when nature hangs in the balance and familiar themes drop out and alien ones take over.

After all, it was when the Bering Sea dropped to record low levels between 15,000 and 20,000 years ago that North America became linked with Asia by a land bridge that afforded easy access to the Americas for both Asian aborigines and fauna. For a few thousand years North America was little different from Asia. Very few creatures went west the way a sucker, a freshwater fish species, apparently did. Almost all went eastward across the Bering isthmus.

Throughout geologic history ice bridges and land bridges played major roles in the movement back and forth of locomotory species of mammals and even a few reptiles and amphibians. They still do.

Birds didn’t need land or ice bridges to spread out. Locally, the Napeague isthmus crossing to Montauk is an active land bridge that still filters things coming and going as mentioned many times previously in this column.

Pitch pines, now attacked throughout Long Island as far east as Napeague by the southern pine boring beetle, only recently crossed that isthmus to get to Montauk. Before their arrival, chipmunks, which were very scarce on the South Fork in olden times, made it all the way to the Point. Now woodchucks and flying squirrels, which only recently arrived on the South Fork, are on their way to the very end of Long Island by this route.

How did the Gull Island meadow vole, or field mouse, make it all the way to Big Gull Island only to eventually be extirpated there by the end of the 20th century? By a land bridge? By an ice bridge? On floating cakes of sea ice? That question has yet to be answered.

There have been several times throughout the 1700s, 1800s, and 1900s when the winters were so cold that Gardiner’s Bay and Shelter Island Sound froze over. Animals came and went across the ice.

When the colonists arrived, the story goes, Gardiner’s Island didn’t have the red fox. But every once in a while when the bays freeze over, foxes make it to Gardiner’s Island. But it takes two red foxes to tango, and apparently two of the opposite sex that like each other have never made it there at the same time. Foxes are not known for their long-distance swimming ability.

In the coldest winters of the 1980s iceboats plied the frozen water of Three Mile Harbor, and even for a day or two Noyac Bay. Parts of the Great South Bay freeze up regularly, as do Mecox Bay and Georgica and Hook Ponds. Mecox Bay plays host to an occasional iceboat. The Great South Bay was known for them. Interestingly, iceboats with sails predate by many generations the summer season’s stand-up sail vehicles of the kind that can fill Napeague Harbor on a July weekend.

Shelter Island has the same mammalian fauna and much of the herptile fauna as the rest of eastern Long Island. Either it was once connected by land or by ice bridges to one or both of the forks, or it was reached by drifting on makeshift rafts. It’s hard to imagine a salamander species, almost all of which are completely inactive and hibernating during the winter, slithering over on the ice. Neither do they do well in saltwater.

Fish are another matter. Many of those we find around in the winter, such as winter flounders, a few gobies, killifish, pouts, and members of the codfish family, have antifreezes in their system. A local ichthyologist, Dr. Howard Reisman, while teaching at now-defunct Southampton College for more than 40 years, was one of those scientists who found that out. For those fish species that can tolerate such a wide range of temperatures between summer and winter, they have an advantage. Winter is a slow time metabolically for most temperate fish, reptiles, and amphibians. A fish that can stay active at very low water temperatures practically has the place to itself. No competition, but there is always danger lurking — if not bigger fish, then seals.

Among the local mammals, the chipmunks and woodchucks are, we hope, safely ensconced underground. It’s tough on the squirrels, foxes, deer, cottontails, raccoons, and opossums when the ground is snow-covered and the freshwater is frozen solid. Best to lie up in a sheltered place and let the freeze blow over. Mice, on the other hand, stay active. Field mice burrow through the snow along the surface of the frozen ground to get food and to get from place to place.

Two questions come to mind if the freeze persists deep into February. Will waters freeze to the extent that coyotes will find their way to Long Island in numbers that will allow them to settle here and reproduce? Will the black-legged, lone star, and dog ticks survive in large numbers? My bet is that they will do just fine. Earlier this year I took three black-legged ticks and submerged them in a lidded container of tap water. They remained lifeless after sinking to the bottom for three months — August, September, and October — at room temperature. Then, I removed the lid and poured the water down the drain without losing a tick. Within a minute of being exposed to air, they were up and wandering around.

The next experiment, come spring when ticks get active again, will be to put them in the freezing compartment of my refrigerator for different lengths of time. I’ll find out just how indestructible these tiny arthropods can be.

Larry Penny can be reached via email at [email protected].