Winter provides the Shenandoah National Park the opportunity to be the host of many northern nesting birds.† These seasonal guests include northern juncos, brown creepers, red-breasted nuthatches, golden-crowned kinglets, yellow-bellied sapsuckers, short-eared owls, pine siskins, purple finch, sparrows (white-throated, American tree, and fox), rough-legged hawks, and a few others.† May of these can be found breeding in the Appalachian plateau of West Virginia and North Carolina, where it is of higher elevation and cooler, but not in our Park.† Contrary to conventional thought, we do have robins in winter.† There is a shift in robin populations in the fall, so that our winter robins have bred in New York and Pennsylvania while our breeding stock is sunning down in the Carolinas.† If you spend much time in the woods, you will see them in large flocks in the treetops.† Unlike most birds, they continue to call throughout the winter.† Just donít look for them in your front yard until spring, when the worms have come back to the surface.† In fact, the Indians call the March full moon the worm moon, for this reason.
Of all the birds that reside in our winter forests, the golden-crowned kinglet must have the toughest life.† To start with, it is our smallest winter bird; smaller than our summer warblers, weighing in at two ounces and a total head to tip of tail length of 3 ĹĒ.† This large surface area to volume ratio makes heat loss a major issue.† To make things more difficult, the kinglet is a strict insectivore, passing over the available seed supply for the harder to find over-wintering insect eggs.† If life for this tiny insectivore wasnít already hard enough, now Man has introduced the hemlock woolly adelgid.† This aphid-like insect has been killing the hemlock groves throughout the kingletís wintering range, effectively eliminating its favorite habitat for both food and shelter. Look for the golden-crowned kinglet flitting about in these hemlock groves in small, lose groups, often with titmice and chickadees, and listen for itís weak high-pitched trill that these birds use to communicate amongst themselves.†
Not all birds have it as bad as the golden-crowned kinglet.† Surprisingly enough, great horned owls have been on their eggs since January, and the barred owl is mating at this time.† Listen for itís Ďwho cooks for you, who cooks for you-allí.
I always hope to hike in the Shenandoah National Park with a snow cover.† Despite the lack of food and warmth, the great number and variety of animal tracks tells us how many animals do find a way of surviving these stressful winters.† Small mammals, such as white-footed mice, voles and shrews, are most common, along with the ubiquitous deer.† But bobcat, fox and coyote are also routinely found, and even bear tracks are often seen, a reminder that not all bear chose to spend the winter in hibernation (if one chooses to apply that term to bear).†
Speaking of black bear, birthing is taking place now (late January or early February) with the cubs weighing only 6 to 10 ounces and about 8 inches long; helpless, hairless, and eyes closed.† The good news for the sow is that she will often remain in deep sleep throughout the birth!† The unusual thing about the black bear pregnancy is that after a summer mating (with the male and female together over a two week period in late June or early July) and fertilization, the embryo undergoes an arrested state of development for five or six months.† Known as delayed implantation, this enables the bear in the fall to concentrate its energy on fattening up on the available mast crop, instead of expending its energy on mating.† Interestingly, if the mast crop fails and the sow fails to put on adequate brown fat before entering the winter dormancy, the embryo will abort.† Thus, the delayed implantation prevents the sow from investing in a pregnancy before her food reserves are established.† The actual gestation period of 6 to 8 weeks begins in November or December.† Delayed implantation occurs among many of the weasel family as well.
And, speaking of bobcats, if youíre staying at one of our cabins in the woods at this time of the year, you might be lucky enough to hear the blood-curdling scream of what sounds like a wild banshee woman.† If this sounds about right, then youíve heard a male bobcat hollering for a woman.† February and March are the prime breeding months for them.