We are now entering the darkest month of the year, the two weeks before and after the winter solstice. During this period the Northern Hemisphere is maximally tilted away from the sun and solar radiation is least direct. The Arctic is in the heart of its perpetual winter dark-ness and, those of us at more southern latitudes, are experiencing the shortest days of the year.
While this is the darkest month, it is generally not the coldest period in the Temperate Zone. The ground is not yet frozen solid and the larger lakes remain open; as a consequence, the surface of the Earth is still radiating heat into the lower atmosphere. By mid January, this warming effect is significantly reduced and, though the days are lengthening, the coldest temperatures occur.
As darkness extends its reign, the night hunters gain an advantage; equipped with superior night vision, these predators also benefit from longer hunting periods. It is, indeed, the season of the owl and, in concert with this hunting advantage, their breeding cycle will soon begin.
