Shortest Day Of The Year Upon Us
The first day of winter, December 21st, is defined by the year’s shortest day and longest night. The good news is that days get just a bit longer each day thereafter.
The first day of winter is often called the winter solstice, but the solstice is actually a moment in time, not an entire day. The solstice in the Northern Hemisphere occurs when the Sun is directly above the Tropic of Capricorn in the Southern Hemisphere. It is that instant when the North Pole is tilted furthest from the Sun (23.5 degrees). This year the solstice occurs on December 21st. The exact moment varies geographically. Think of the solstice as the official shotgun start of winter.
Meanwhile, the South Pole becomes the Land of the Midnight Sun with 24 hours of daylight, while the North Pole experiences the exact opposite. There is no daylight north of the Arctic Circle this time of year.
The exact times and dates of these events vary from year to year due to the lack of precision of our calendar year, the exact motion of the earth, and the “wobble” of the earth on its axis.
Even ancient cultures observed the predictable changes in day-length associated with the solstice. There was no guarantee of surviving winter; starvation was common. So before winter gripped temperate and northern areas, people celebrated with feasts. Most farm animals were slaughtered so they would not have to be fed during the winter. Fresh meat was a luxury. Alcoholic beverages were fermented and ready to be quaffed. This is one reason we celebrate year-end feasts to this day.
To mark the solstice, I step outside after dark and listen. Great horned owls are the quintessential “hoot owls” people sometimes hear, but seldom see, and they’ve already begun courting; their song is a series of muffled hoots. The male has a deeper voice, so it’s easy to detect a dueting pair. Listen for a series of five to seven simple hoots. A five-syllable song may suggest the phrase, “Don’t kill owls, save owls!”
If I’m lucky, I may also hear a barred owl – “Who cooks for you? Who cooks for you-all?”
By mid-January, great horned owls have usually claimed an old crow or red-tailed hawk nest. They don’t bother building their own. Sometimes they’ll choose an old tree cavity, if there’s one big enough within their territory. Older females may lay eggs by the end of January, though many probably delay egg-laying until February.
Clutch size averages two to three eggs, and incubation takes about 35 days. The female does most of the incubating. After hatching, both parents provide a steady supply of rabbits, rats, mice, opossums, and skunks for the owlets.
Another nocturnal sound of the solstice you might hear near bird feeders stocked with sunflower seeds or peanuts are high pitched squeaks. If you hear these squeaks, turn on a porch light or direct a powerful flashlight to the feeders.
Flying squirrels, sometimes called fairy diddles, are common in deciduous woods but strictly nocturnal, so most people never see them. But they are quite social during the winter and sleep in tree cavities and nest boxes in groups of four to 12 individuals. When they emerge to forage after dark, they do so as a group, so if you see one at a feeder, you’ll probably see several.
And if you’re lucky enough to see a group of flyers in action, you’ll notice they do not fly. They glide from tree to tree courtesy of a flap of skin that runs from wrist to ankle on each side of the body. Upon takeoff, this skin billows and permits a controlled glide from tree to tree. Most flights are short, 30 to 40 feet, but biologists have observed flights as long as a football field.
Whether you celebrate the solstice with a feast, by listening for owls, or watching flying squirrels, it’s good to know that after three months of increasingly shorter autumn days, photoperiod begins to lengthen. And that is the one absolutely reliable environmental signal that winter won’t last forever.
Send questions and comments to Dr. Shalaway at email@example.com