Beautiful October, changing landscape

October brings predictable and noticeable changes to the natural world.

Day-length shortens, and temperatures dip. The first frost is imminent. Reds, oranges, and yellows brighten the leaves on trees.

Chipmunks cluck as they scurry about searching for food. Bird migration peaks. Nocturnal voices of katydids and crickets get slower and quieter.

In October, sumac thickets, heavy with clusters of dark, red berries, turn flaming orange. Virginia creeper leaves turn blood red. Soon red maples, sassafras, flowering dogwood and poison ivy will join the scarlet brigade. By the end of October, oaks and hickories add their earthy tones to the autumnal landscape.

And the final blooms of summer — goldenrod and asters — add splashes of color to hayfields and pastures.

Biological clocks

The timing of the fall extravaganza is set by photoperiod (day length) and fine-tuned by temperature. Virtually all animals and plants have internal, 24-hour “biological clocks” that keep track of daily time.

Any clock, however, is worthless unless it can be set to some standard. Photoperiod is the one absolutely reliable standard living systems can depend upon, year after year after year.

For each tree species, there is a critical day length during which green chlorophyll breakdown begins and other pigments reveal themselves.

HummersMost hummingbirds have already headed south. But it is shorter days, not dwindling food supplies, which trigger hummingbird migration.

Most hummingbirds have already headed south. But it is shorter days, not dwindling food supplies, which trigger hummingbird migration.

I usually keep one nectar feeder filled for stragglers from farther north until I don’t see a hummer for at least 10 days. That often takes me to mid- to late-October.

Maturing pods of milkweeds are another sure sign that it’s October. Keep an eye on them, and when the pods split, collect the silky plumed seeds to plant next spring.

Monarch butterflies will thank you by laying eggs on the tender spring growth.

‘Hangry’ yellow jackets

All is not perfect in October, however. Warm fall days bring out the worst in yellow jackets. Just ask anyone who’s been to an outdoor fall festival. A belligerent yellow jacket on the rim of a cup of cider can lead to a sting on the lip and ruin an otherwise idyllic day.

But there’s a simple reason these familiar wasps turn nasty in the fall — they’re hungry.

Yellow jackets are active all summer long, yet unless you run over their nesting burrow with the lawn mower, they’re rarely aggressive. But on warm fall days, they get mean. The simple explanation is that the social structure of the colony breaks down, there’s not much to eat, and they will soon die.

Deer are everywhere

Finally, the greatest dangers to people in October and November are the unpredictable movements of white-tailed deer.

The rut (deer mating season) is on, and bucks are preoccupied with finding receptive females. Both sexes seem oblivious to traffic. Hunters further disrupt the deer’s normal movement patterns, so there’s no telling where they’ll appear.

The net result is that from mid-October to mid-December, deer can appear on highways anywhere and anytime. They are most active, however, from dusk until dawn. To stay safe, keep these tips in mind.

• Deer are everywhere. You’re as likely to encounter one on a city street as on a rural interstate, so slow down.
• Deer behave unpredictably. When you see one up ahead, expect it to cross the road in front of you.
• Deer are social and often move in groups. If you see one cross the road, expect several more to follow.
• When there’s no oncoming traffic, use high beams. They will illuminate the eyes of deer on the sides of the road.
• If there are young, inexperienced drivers in the family, warn them of this danger.

October is the heart and soul of fall, and it brings with it nature’s best and worst. Enjoy it while it lasts. Then we can look forward to spring.