With the coming of October, we reach the end of the growing season. With the decreasing solar energy, the rate of plant photosynthesis and animal metabolism has significantly slowed down (with the notable exception of the warm-blooded mammals and birds). The days are getting colder and the killing frosts are near at hand. The mammals and birds of the forest are stimulated to ingest as many calories as possible before the onset of winter. And the usable form of the energy that supports our diverse faunal community takes is largely based upon the hard mast crop produced by the oaks and hickories. Prior to this last century, the American chestnut was also a major constituent of this energy supply. It is believed that the chestnut was the dietary staple of the Passenger pigeon, supporting their annual fall migration. The value of the chestnut was not only in it’s prominence in the forest composition, but also in it’s habit of producing a large crop of fruits every year. This is unlike the oak species, which may have a good fruit producing ‘mast crop’ only once every five years or less often.

October is a very busy time for wildlife. Much of our wildlife counts on the acorns and nuts to provide them with the energy necessary to get them through the winter season of scarcity. Bear, deer, raccoon, and other mammals join the food fight with grouse and turkey. And this doesn’t include the fungi, bacteria, arthropods and micro invertebrates that count on the mast for their food supply.

Chipmunks cache their acorns, nuts and conifer seeds in large hiding places called middens. Well-developed cheek pouches have been known to hold up to 32 beechnuts or 70 sunflower seeds. Red squirrels also use the midden approach. Gray squirrels chose a different method of storage, preferring individual holes for each acorn or seed. Stored foods are found by smell, not memory. This is the time of year mass movements of squirrels have historically occurred. Such movements are necessitated by local high populations and erratic annual acorn mast crops. A famous naturalist of one hundred years ago, Ernest Thompson Seton estimated one mass movement at more than one billion individuals in 1920. A more recent mass movement on a reduced scale was reported in October of 1968 in the southern Appalachians of TN, GA and NC. This followed a mast crop the previous year, resulting in an abundance of young squirrels. Unfortunately, 1968 was a poor mast year, resulting in a major food shortage.

The mast crop is so important to the black bears that all other physiological functions take second priority. This even includes mating. With an eight-week gestation period, late fall is the time black bear should be getting serious about mating. However, such activity would call for much time and effort being expended seeking females and defending territories, something that would severely detract from the important function of fatting up for the upcoming winter season. So, nature has provided a unique solution to the bear’s dilemma known as delayed implantation. The black bear mates in late spring, when food resources are prevalent, but, shortly after fertilization, the egg’s growth is arrested, and lays dormant within the female for six months. Only in November, does the egg implant on the uterus wall and its growth continue, allowing birthing to occur in late January. 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.

This delayed implantation also occurs among most of the weasel family, including minks, marten, skunks, river otters, long and short-tailed weasels and the recently re-introduced fisher. The fisher is the record holder with a delayed implantation period of ten to eleven months resulting in a birth a year after mating (an average of 352 days, which includes a gestation period of 30-50 days). The female is quickly inseminated again (in fact, she is not pregnant for only about ten days), so that birthing takes place every year.

What else is happening in October? Rattlesnakes will enter their dens in our region from the last week of September until the middle of October, often denning with copperheads and a few black rat snakes. Other snakes will burrow in individual holes, nocks and crannies. And many of our turtles will be hatching and leaving their nests for winter dens underwater or in individual burrows. An exception to this is the painted turtle, which, after hatching, will remain in its nest with the other juveniles until spring. Lizards and the myriad of almost all other life forms will seek the protective warmth of the deeper soil horizons or rotting wood and be gone from sight until next spring.

Aquatic red-spotted newts are developing lungs and becoming the terrestrial red efts, while our native brook trout are spawning in the cold mountain streams. Look for their shallow foot-wide concave excavations in sandier stream sections. And our Shenandoah National Park wintering birds are back, including the northern junco, brown creeper, winter wren, red-breasted nuthatch, golden crowned kinglet, white-throated sparrow, American tree sparrow, hermit thrush, short-eared owls, and yellow-bellied sapsuckers. (For clarity, the first five can be found year round in the higher elevations of WV south to the Smokies.)

October ranks second only to April when the most change can be observed in the natural world. April is when the forest awakens from its winter dormancy with an explosion of activity. October is when it must finish its preparations for the oncoming winter season. While the beginning of the month is still dominated by the green of the forests, insects singing, and wildlife busily preparing for winter, by the end of the month, October will have experienced its first killing frosts. And with it, the growing season of our forest community will have been completed, and the onset of the next season of scarcity and pursuit of survival will be upon us. And it’s all because of the reduced solar energy available to fuel our ecosystem.