It’s not easy being a female porcupine. You mate in the fall and are either pregnant (7 months) or lactating (4 months) for the next 11 months before you have one month’s break and begin this cycle all over again. This time of year porcupines are giving birth to one young that is covered in fur and quills and weighs about a pound. The young porcupette is born headfirst in a sac, in order to protect the mother from quill damage. Its quills are soft at birth, but harden within an hour. (Thanks to Kay and Peter Shumway for photo op.)
Hibernation has come to an end for painted turtles in central Vermont, or at least for the early risers. Painted turtles actually became active a while ago, beneath the ice before ponds were completely thawed. Once some of the ice melts, they are quick to climb up and bask in the sun on any available floating log or rock, or even on the melting edge of the ice. Having spent the winter in the mud at the bottom of the pond at the rather brisk temperature of 39 degrees F. (at 39 degrees F. water achieves its greatest density and sinks to the bottom of ponds, which is where the turtles are), painted turtles are more than ready to get warm. Like black bears, painted turtles find March and April the most challenging months of the year. More of them die now than at any other time, due primarily to a shortage of food.
Recent discovery of black bear tracks and scat confirm that hibernation has come to an end, at least for some bears. During the winter black bears lose an average of 23% of their body weight. Because there is a scarcity of food when they emerge from their dens, black bears continue to subsist off the fat that they put on last fall, and thus continue to lose weight. The diet of black bears is high in carbohydrates and low in proteins and fats. When hibernation is over, they head for any available succulents and protein-rich food, including bird feeders.
A white-tailed deer’s diet consists of a wide variety of herbaceous and woody plants, the ratio of one to the other being determined by the season. Fungi, fruits and herbaceous plants form much of the summer diet. Dried leaves and grasses, acorns, beechnuts and woody browse are important autumn and early winter food. After snowfall, the winter diet consists mostly of woody browse (twigs, leaves, shoots and buds) from many different trees (maples, birches and cedars among them). Come spring, deer eat buds, twigs and emerging leaves. Deer are ruminants (as are cattle, goats, sheep and moose). They have a four-chambered stomach, which is necessary in order to digest the cellulose in the vegetation they consume. Food goes first to the rumen, the first of the four chambers, which contains bacteria and other microorganisms that help digest the cellulose. Food is circulated from the rumen back to the deer’s mouth by the second chamber, or reticulum, and the deer ruminates (“chews its cud”). The third chamber, or omasum, functions as a pump, sending the food to the final chamber, the abomasum, where the digestion process is completed.
Ice is starting to form on ponds, and days are numbered when beavers can be out grooming themselves on land or eating freshly-cut branches. As long as the ice is thin enough to crack by swimming up under it and bumping their heads against it, they will do so, for soon it will be thick enough to lock them into their pond. Life under the ice is challenging. At 32 degrees F. a beaver’s resistance to heat loss in water is about 1/8th of that in air at the same temperature. This is due to the fact that its fur is compressed in the water, allowing the insulating air between the hairs to escape — a beaver’s pelt accounts for about 24% of its total insulation in water and body fat is responsible for the rest. Heat is also retained through a beaver’s tail and hind legs, which serve as heat exchangers. In the summer, a beaver can lose 25% of its body heat through its tail, but it only loses 2% in winter. Even so, it’s no wonder beavers risk getting a headache in order to see the sun for the last time until spring.
On the inside of the hind legs of all white-tailed deer are glands called tarsal glands. They consist of a tuft of long hairs coming from an area of skin in which are located glands that secrete a fatty substance. This fatty substance adheres to the long hairs. When deer urinate, they often assume a crouched posture, causing their urine to run over these hairs. The lipid, or fatty material, on the hairs causes some of the urine that runs over them to remain there. Excess urine is licked off by the deer. The combination of fatty material and urine gives the glands a unique smell (not the typical deer urine smell.) During the breeding season mature bucks urinate on the tarsal gland much more frequently, and don’t lick off the excess urine, which creates a distinctive rutting odor . This practice is referred to as “rub-urination.” All deer urinate on these glands throughout the year.
This may well be the last month until spring in which signs of active black bears can be found – cold temperatures and a poor beechnut and acorn crop may hasten their retreat into their dens. A black bear’s track is fairly distinctive, if only due to its size: 3 ½”- 6” wide by 4”-9” long. Black bears are flat-footed, or plantigrades, and thus you see more than just the toe imprints in a track; the heel pads of the hind feet are larger than those of the front feet. Black bears have five toes on each foot. The smallest, outside toe often doesn’t register. Long, curved nails on a black bear’s front feet are used for marking trees and climbing; the hind feet nails are much shorter.
By the end of this month or the beginning of November, most Eastern Chipmunks will have gathered and stored their winter food supply underground in a special chamber which they will visit every two or three weeks throughout the winter, grabbing a bite to eat. Up to half a bushel of nuts and seeds can be stored here, which means many trips from the food source to the larder. In order to minimize the number of trips, chipmunks cram their cheek pouches as full as possible. The contents that researchers have found in one chipmunk’s two pouches include the following (each entry represents the contents of one chipmunk’s pouches): 31 kernels of corn, 13 prune pits, 70 sunflower seeds, 32 beechnuts, 6 acorns.
Shorter days and longer nights trigger a flurry of activity for beavers. There is a lodge to be built, rebuilt, enlarged or repaired and a dam to be built, repaired or reinforced. As, or more, important than these tasks is cutting, gathering and transporting a supply of food for winter. Once the pond is frozen, the only food available to beavers is that which they have stockpiled under the ice. Thus, beavers spend many an autumn night adding to a growing pile of submerged branches close to the lodge. More thought is put into the harvesting of a winter food supply than one might imagine. Before cutting down a tree a beaver often tests its readiness by biting into the bark. If it is not in just the right condition — for instance, if there is still too much sap in the tree — they may speed up the drying of the bark by girdling it, and returning in several days to cut it down. If limbs and branches are stored underwater before the bark is ready, they will ferment and sour, making them unfit for food.
The mating season for moose (Alces alces) is just starting, and it peaks around the end of September or the first week in October. By this time bulls have shed the velvet that provided a blood supply to their antlers while they were growing during the summer. Occasionally you see the remains of the velvet hanging from their antlers at this time of year (see photograph). During mating season, bulls are rushing through the forest, seeking a receptive cow and engaging in mock battles with other bulls for the female’s attention. A bull uses his antlers in these challenges, engaging in “antler-pushing” with other males. He also uses his antlers as a tool for thrashing brush and for rooting plants from the bottom of ponds.
Birds have a number of ways of keeping cool, which is a good thing, given the number of hot days we’ve experienced this summer, and probably for summers to come. They don’t sweat, nor do they pant, but birds do have several behavioral adaptations which reduce their temperature. Often, while exposed to the relentless heat of the sun, Great Blue Heron nestlings resort to what is called gular fluttering. They open their mouths and “flutter” their neck muscles, promoting heat loss – an avian version of panting. An even easier behavior to observe is the position Great Blue Herons will often assume on a hot day. They droop their wings (see photograph) while standing, which allows air to circulate across their body and sweep away the excess heat.
You can often tell whether a snake is active in the day (diurnal) or during the night (nocturnal) by looking at its eyes. Diurnal snakes, such as the pictured Common Gartersnake, typically have round pupils and moderate-sized eyes. Many nocturnal snakes have large eyes and many also have vertical, elliptical pupils. A round pupil is able to close tightly to a pinpoint opening, allowing a minimum amount of light to enter the eye on very bright days. In contrast, a vertical pupil can open wider than a round pupil to allow more light to enter the eye, a useful adaptation for night vision.
Most terrestrial snails are herbivorous, feeding on a wide range of vegetation. The snail’s mouth is on the bottom of its head near the shorter pair of tentacles. Snails (and all molluscs) consume their food not with mouthparts, like insects, or teeth, like mammals, but with a rasping tongue or radula. Snails don’t bite their food, but rather, rasp or scrape it. The radula is covered with rows of tiny “toothlets” which rasp particles away from vegetation and move them back towards the snail’s gullet. Different species of snails have differently-shaped toothlets. The radula is used by the snail not only to process food, but to clean bits of dried mucus from its shell. Supposedly if you listen hard, you can actually hear a rasping sound when the latter is occurring. (If you look hard, you can just barely see the orange radula of the land snail in the photograph.)
Like all amphibians, toads breathe through their skin as well as with their lungs. When a toad is inactive the skin usually absorbs enough oxygen to meet its needs. During and after activity a toad often supplements its supply of oxygen by actively breathing air into its lungs. Unlike mammals, amphibians do not make regular and rhythmic breathing movements but bring air into their lungs spasmodically as the need arises. Air enters the toad’s mouth through its nostrils, and by raising the floor of its mouth, the toad forces the air into its lungs. (Photo is of an American Toad.)
Given the amount of time porcupines spend in trees, it’s not surprising to see that their feet are well adapted for climbing. Long, curved nails that grip the bark, as well as “pebbly” foot pads designed to prevent slipping allow this prickly rodent to climb just about anywhere it wants to. (Hind foot pictured.)
Can you find the brown creeper that’s on the trunk of this black cherry tree? This is cryptic coloration, a form of camouflage in which an animal blends into its environment, at its finest. A forager of insects and spiders tucked away behind and in the crevices of bark, the brown creeper starts its search at the base of a tree, climbing upward and often spiraling around the trunk until it nears the top. It then flies to the base of a nearby tree to begin the process again. As W.M.Tyler wrote in 1948 in Bent’s Life Histories of N.A. Birds, “The brown creeper, as he hitches along the bole of a tree, looks like a fragment of detached bark that is defying the law of gravitation by moving upward over the trunk, and as he flies off to another tree he resembles a little dry leaf blown about by the wind.”