There is nothing like heading out on snowshoes to look for tracks after a major snow storm has passed. The pristine snow is often untouched, except for a few brave souls who have ventured out. Most of the mammals that are active in winter hunker down until well after it has stopped snowing, but the mink (Mustela vison) is not about to lose a night of hunting and its tracks can often be found the morning following a storm. Like other weasels, this bounding carnivore often leaves diagonally paired tracks, but unlike other weasels, its tracks are consistently the same distance (1 to 3 feet) apart. They also are most prevalent in or near wetlands. Although a fierce predator, the mink also has a playful side, much like its cousin, the river otter. Mink are known to dive under the snow and make short tunnels. Even more delightful to come upon are the slides that mink often make down inclines. If you see a groove in the snow about 3” in diameter, with paired tracks at either end, you have come upon such a slide.
I am taking a short break from writing my Naturally Curious blog and will be posting again at the end of next week. This wild partridge (ruffed grouse) and I wish you a wonderful holiday filled with many outdoor discoveries!
If you happen to notice a ¾” to 1 ¼”- long, brown kidney-bean-shaped or round structure on a blueberry bush this time of year, you’ve come upon the blueberry stem gall – a summer and winter home for a dozen or so wasp larvae that will pupate and emerge in the spring as very small (less than 1/8”) black wasps (Hemadas nubilipennis). Last summer a female wasp laid her eggs in a tender, developing blueberry shoot. She then climbed to the tip of the shoot and stabbed it repeatedly, causing considerable damage. Within two weeks the eggs hatched, and the larvae began feeding, which, along with the egg-laying, stimulated the formation of the gall. Initially a blueberry stem gall is green and spongy; by fall it turns red, and by late autumn, it is brown and woody. Next summer, look for multiple holes in these galls that were chewed by the exiting wasps.
As members of the weasel family (Mustelidae), fishers and mink have five toes on both front and back feet. Often all five digits do not register, but in prime tracking snow, you can often see them. Typically, mink tracks are found near a body of water, and fisher tracks are found under a canopy, not in the open. Where you have both water and trees, it’s possible to see signs of both animals. In general, the larger the animal, the larger its tracks. In this photograph, the mink tracks (smaller, in the middle) are heading towards the top of the photograph, and the fisher tracks (top most and bottom most) are heading towards the bottom of the photograph. Although not pictured here, both of these carnivores engage in snow sliding, much like their cousin, the river otter, and the resulting grooves are occasionally found when the snow is a bit deeper than it is now.
As an impressive number of people knew, the black markings on the yellow birch were caused by fungi that create what is called “spalting” in trees. When the temperature (70 – 90 degrees F.) and moisture content (30%) of certain trees (birch, beech and maple, most commonly) is just right, colonies of fungi infect them. There are different forms of spalting – the pictured fine black lines are referred to as “zone lines.” They are created when incompatible colonies of fungi come into contact with each other and lay down barriers to separate their territories. The presence of spalting indicates that the decay process has begun. Spalted wood’s natural beauty is highly regarded by wood turners and is held in contempt by the lumber industry (with time, the wood softens and weakens as it decomposes). As the Ohio Dept. of Natural Resources so eloquently states, “Spalted wood embodies all that is curious in the natural world. It is formed by unseen organisms at a specific time and place that only it knows.” (Thanks to John Gutowski for yesterday’s yellow birch mystery photo and the HobbitHouse for the bowl photograph.)
White-tailed deer are known to eat over 600 species of plants in North America. They consume, on average, about 5 to 8 pounds of food for every 100 pounds of body weight, per day. As a result, a deer, on average, defecates about 13 times a day. A crude but somewhat accurate way to estimate how many white-tailed deer are in your area is to count the number of scat piles you find in a square mile within 24 hours, and divide this number by 13. A little snow on the ground would make this particular method of population estimation a lot easier!
Common redpolls (Acanthis flammea), named for their red cap, are small northern finches that breed from the southern edge of the Arctic tundra down into the Canadian coniferous forests. Their size, shape, actions and voice are similar to those of goldfinches and pine siskins. The bulk of the common redpoll’s diet consists of the seeds of several different trees, including birches, alders and willows, as well as grass and weed seeds. While their winter range extends southward as far as Massachusetts, in winters when the seed crop of these trees is exceptionally poor, large numbers of redpolls come even further south into the U.S. seeking food, and these visits are referred to as irruptions. The numbers of redpolls at feeders throughout northern New England, as well as their presence in states further south confirm that the winter of 2012-2013 is such a year. Look for large flocks moving about in undulating flight over fields, alighting on weeds, as well as at and under feeders, where millet and sunflower seeds attract them. Between the redpolls’ brilliant red crowns and their constant twitter, they are hard to miss!
In December, in Vermont, you don’t expect to come across an active spider, but yesterday that’s exactly what happened. A Green Long-jawed Orbweaver (Tetragnatha viridis) was crawling on the duff underneath a stand of hemlocks. Upon noticing me, this slender ¼” spider immediately formed itself into a straight line, with four of its legs stretched forward, and four backwards. Assuming this shape enables these spiders to be very well camouflaged on a blade of grass. There are 25 species in this genus in North America, all of which are called “stretch” spiders, referring to their elongated body form. They are very agile and can navigate on the surface of water very well.
Long before the beetles and flies move in to get their share of a dead carcass many meat eaters have usually taken advantage of the easy meal. A motion camera on a dead white-tailed deer recently captured the images of 12 scavengers over a six day period. They included an opossum, several coyotes, a raccoon, red fox, striped skunk, American crow, raven, turkey vulture, red-tailed hawk and bald eagle. By the end of this time, there wasn’t much left except for bare bones, which, as winter progresses, will eventually be eaten as well. Not a shred is wasted – nature knows how to recycle and has been doing it for eons.
The Ruffed Grouse has both behavioral and physical strategies for dealing with the cold, snow and ice of New England winters. Three of the physical changes that take place in the fall are evident by looking closely at a grouse’s legs, feet and beak. The feathers on its legs grow thicker and further down towards its feet, to provide better insulation. Small comb-like growths of skin, called pectinations, develop along either side of each toe. These increase the surface area of a grouse’s foot, and serve as snowshoes in deep snow. They also help the grouse cling to icy branches while it quickly snips off poplar and other buds at either end of the day. And on its beak, feathers expand downward to cover its nostrils, slowing the cold air and giving it a chance to warm up before it is inhaled by the grouse.
My apologies. I inadvertently mis-identified today’s flowering plant, Virgin’s Bower (Clematis virginiana). There are several members of the Buttercup family, Ranunculaceae, that are very similar, however, Clematis virginiana is pictured! It is a native perennial vine that is also known as Devil’s Darning Needle, Love Vine and Woodbine, among other common names. The styles, or female structures of its small, greenish-white flowers, develop into long feathery appendages on each of its seeds. Together the clusters of white “hairy” fruits give this plant its common name. The delicate beauty of its seed heads cannot be denied.
The relatively warm, wet start to winter has provided us with the opportunity to see riverside tracks that might otherwise not be evident. Raccoons are known for their ability to go anywhere and get into anything and the reason for this dexterity is revealed in their tracks. Both front and hind feet have five long toes. Although the “thumb” is not opposable, it is long enough to grasp things. Because of this dexterity, raccoon tracks can vary widely. In mud and snow, they often resemble small human hands. Typically the toes of the front feet are more splayed out than those of the hind feet.
Tree buds are formed in the summer, so if you look at a tree today, it will have buds on it, in the axils of where the leaves used to be (on deciduous trees). There are two kinds of buds – leaf buds and flower buds (flower buds are typically fatter than leaf buds). Both are usually covered with scales which help seal in moisture to protect the bud from drying out during the long, dry winters when water is frozen and therefore unavailable. Different types of trees have different types and numbers of scales. There are a few trees whose buds lack scales completely; these buds are referred to as “naked.” Witch hazel (Hamamelis virginiana), bitternut hickory (Carya cordiformis) and hobblebush (Viburnum lantanoides) all have naked buds. In the photograph, a hobblebush leaf bud is on either side of a flower bud.
Have you ever noticed that the color of some lichens is a more intense green after they get wet? There’s a very good explanation for this phenomenon. Lichens are made up of an alga or cyanobacterium and a fungus. The alga or cyanobacterium makes the food, and the fungus absorbs the water. A typical lichen has a three-layered structure. A middle layer containing algal cells entwined in threadlike fungus fibers called hyphae is sandwiched between two layers of fungal tissue. Lichens that turn bright green after it rains contain green algae which contains chlorophyll, a green pigment. When it rains, the fungus (which surrounds the algae) soaks up water like a sponge, causing the fungus to become more transparent, which allows the green pigment of the algae to be seen more clearly.
If you lived in New England in the early 1800’s, the sight and sound of a Northern Mockingbird (Mimus polyglottos) would not be familiar to you. In the mid to late-1800’s they began extending their range northward in eastern North America to the point where they are now year round residents throughout New England. This range expansion is largely attributable to changes in habitat (more fields and shrubby areas), as well as the demise of the practice of capturing mockingbirds for the pet trade. However, during the last 25 years Vermont has experienced a 26% decline in breeding mockingbirds, due largely to diminishing habitat, according to the Vermont Center for Ecostudies’ 2nd Breeding Bird Atlas.The Northern Mockingbird is known for its ability to mimic other birds’ songs (a male’s repertoire often contains more than 150 songs, which changes and can increase as the bird ages). In the spring and fall, if you hear a bird singing at night, especially during a full moon, it is often an unmated male mockingbird. At this time of year, you’re more likely to see, not hear, a Northern Mockingbird.