Oaks are generally divided into two major groups: red oaks and white oaks. Red oaks have bristle-tipped leaves, acorns with hairy shell linings and bitter seeds that mature in two seasons. White oaks have leaves lacking bristles on the lobes, acorns with a smooth inner surface that are sweet or slightly bitter and mature in one season.
Bur Oak (Quercus macrocarpa). also called Mossycup Oak, is in the white oak group and is easily identified by the corky ridges on its young branches, deeply furrowed bark and acorns with knobby-scaled caps (cupules) with a fringed edge. This member of the beech family (Fagaceae) derived its common name from the resemblance of its heavily fringed caps to the burs on a Chestnut tree, though the caps only half cover the nut. Common in central U.S., Bur Oak is relatively uncommon in New England, occurring in in central Maine, New Hampshire, the western edges of Massachusetts and Connecticut, and the Champlain Valley in Vermont.
If you have oak trees in the woods near you, chances are great that their acorns attracted wildlife this past fall, one of which was most likely a Gray Squirrel. Unlike Black Bears, Wild Turkeys and White-tailed Deer, which eat acorns immediately upon finding them, Gray Squirrels tend to cache acorns for winter consumption. They do so by burying them individually, often in fairly close proximity to where they find them. (Red Squirrels also cache food in the fall, but typically bury numerous seeds, mostly conifers and maples, in one spot.) When food becomes scarce, as it usually does this time of year, it is possible to find numerous holes dug in the snow, frequently with leaves and bits of acorn shells littering the snow around them. Tell-tale Gray Squirrel tracks leading to and from these holes identify the excavator.
This winter has brought us several storms that have ended in rain and were followed by plummeting temperatures. Just a few inches down into the powdery snow on top of the ground there is a ¼”-thick crust, and if you dig down several more inches, there is a second layer of ice, roughly 1/8”-thick. When a thick, icy layer of crust forms, it can have a dramatic effect on the lives of wildlife both above and below it.
Some animals are relatively unaffected by the presence of a crust but many predators and prey are significantly helped or hindered by it. Ruffed grouse cannot seek overnight shelter from the bitter cold and/or predators by diving into a foot of soft snow and creating a snow cave (see photo). On the other hand, small rodents have a distinct advantage — mice and voles have several layers of ice between themselves and hungry coyotes, foxes and owls. Snowshoe hares lose the advantage they usually have on deep, soft snow — “snowshoes” that keep them on top of the snow when the bobcat or fisher chasing them has to flounder through it. Turkeys don’t have the strength to dig down through one thick crust, much less two or more, in order to reach hidden acorns. If a deer is being chased, its pointed hooves will break through the crust, slowing the deer down, whereas the crust may well support a lighter predator, allowing it to outrun the deer. Red squirrels have to work much harder to reach their cached winter cones and to create tunnels.
What is a mere inconvenience to us humans literally is costing as well as saving the lives of wildlife this winter.