Nature Notes: From the Inside Out

A cruise around the South Fork last Thursday revealed that about 99 percent of the deciduous tree leaves had fallen. The ground beneath the oaks, hickories, and other trees on either side of the roads in Northwest and Middle Line Highway and Old Sag Harbor Road in Bridgehampton were completely covered with brownish leaves from this year’s crop. The woods, per se, were as they should be, bare trees, underbrush, and a thick leaf groundcover.

Because the canopies were bare, one could see the tops of the trees, trunk, branches, and all as naked as an ancient Greek or Roman statue. One could easily pick out the quarter-size pale-yellow-to-ecru patches of last year’s gypsy moth eggs, waiting for April and May to hatch out. There were some birds perching as well as some flitting here and there above and around the treetops.

Right away, I noticed a circular mass of leaves and twigs about the size of a basketball. I saw several of these clusters as I drove along, all 40 feet or higher, close to or in the treetops. I was reminded of my boyhood in Mattituck on the North Fork, where such sights were common during the winter months.

What I was looking at were dreys, warm cozy places where gray squirrels cozy up during winter storms and freezing or near sub-zero temperatures. Gray squirrels don’t hibernate the way that chipmunks and woodchucks do; they stay active the year round, but, as we humans, need shelter during the worst winter days.

I’ve never seen a squirrel making one of these globular masses, but apparently they make them quickly, because one day you see nothing and the next day you look again and you see one. And I’m not sure how they construct them, but it would appear that it is from inside out more than outside in, say the way carpenters build our houses. Such a method would lend an air of privacy to the degree that the squirrel couldn’t be seen while making its temporary home.

And it would appear that gray squirrels make dreys when holes in hollowed trees are lacking or when garages, sheds, eaves, and attics that provide warmer, drier, and windproof shelters aren’t available to them. I have a pair of adult gray squirrels in my oaky yard and don’t have a single drey.

If the drey is big enough and left empty for a time or abandoned altogether, an opossum seeking comfort and security while napping during cold spells may occupy one. White-footed mice, which are as adept at climbing as squirrels and don’t hibernate, frequently occupy them. Great-horned owls, which very rarely construct their own nests the way most birds do, may modify a drey to fit their breeding needs the way they will take advantage of an empty crow’s or red-tailed hawk’s nest locally. Since their nesting season starts as early as mid-January, they have the pick of the lot when it comes to over-wintering abandoned nests.

During good mast years, when acorns and other squirrel feed is plentiful, a female squirrel may have two litters, one in the summer or even early fall. In such cases the drey is not only used as a winter shelter, but as a shelter for nestling squirrels and their mother.

Some winters are milder than others. Based on my observations over the years, it would seem that there are very few dreys to be found in the mild winters, more by far in the arctic-like ones. Does the number of dreys predict the severity and length of the winter season? That remains to be seen, as so many other factors are in play, in particular the size of the gray squirrel population in a given community.

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