Anyway, our shifts from Daylight Savings to Standard times do not affect organisms other than humans, but the on-going transitions of day length and darkness do affect almost every plant and animal species around us.
My box turtle (photo above by D. Sillman) has been getting sleepier and sleepier as the lengths of sun-lit hours decrease. I have started keeping him exclusively inside the house, but the decreasing time of sunlight has tugged his physiology into a torpor anyway. Turtles that live in outside environments will be pulled all the way into a hibernational homeostasis, but even by moving my turtle in to the constant temperatures of my dining room (where his terrarium is located) he still cannot resist the physiological changes of the season. He ate his last nightcrawler of the year about three weeks ago and won't have another meal (usually really expensive strawberries) until the first or second week in March.
My housecats (photo by D. Sillman) are incredible hair producing organisms! Brushing them or even just petting them in the spring or summer generates great handfuls of shedded hair. The shortening day lengths, though, do act to slow down even their amazing hair production and loss rates. In an outside cat the production of hair without the shedding loss would result in a thick, insulating winter coat. Indoor cats usually don't build up quite as heavy a hair layer but, at least, they slow down their shedding (a little bit, anyway).
As I talked about before, shortening day lengths are the prime stimuli for many of our summer birds to begin their southward migrations. They need to fatten up and leave the area well before food supplies are gone and cold weather has settled in, so getting an early physiological nudge by the shortening days is a great evolutionary advantage. The hummingbirds, the tanagers, the grosbeaks, the robins, and many more species, were each tuned into their own specific day length stimuli, and each in turn built up their fat layers and then headed out toward their overwintering regions. I am glad to report that some of the more northern species (like the dark eyed junco) have responded to their own day length stimuli and have started to arrive to overwinter in our area!
Even humans respond to the shortening day lengths, although the pattern of this response is not always the same in all people. Thyroid hormone seems to either go up or at least get more active in people in the winter. Logically, it stimulates metabolic rate and heat production especially through the metabolism of carbohydrates and the breakdown of the body's brown fat deposits. Cortisol levels also go up in the winter probably acting to shift metabolism over to using fats (both stored and dietary) for energy. But all of these responses are really quite muted compared to other mammalian species probably because of all our technologies that insulate us from the great stresses of winter.
Plants have all sorts of photoreceptor proteins that respond to day length. These proteins are especially sensitive to the duration of darkness. It is the length of the night that drives plant species to flower, or make seed, or senesce. The cessation of chlorophyll production in deciduous tree leaves and its accelerated breakdown reveals the formerly hidden accessory pigments and generates the beautiful color displays of the autumn trees. W. D. Hamilton (the famous "Bill Hamilton" who was a great friend and colleague of Richard Dawkins) suggests that these accessory leaf pigments are not just revealed as the chlorophylls fade but that the lengthening nights actually accelerate their production. These pigments act as deterrents to insects and prevent their overwintering and egg laying in the tissues around the senescing leaves. (Photo by D. Sillman)
So, our hours of sunlight are getting shorter. We are craving more calories and especially more dietary fats (more pizza, grilled cheese sandwiches, and macaroni and cheese!). Sounds like a reasonable trade-off to me! Bring on the winter!