I saw my first skunk of the year this week. It was on the side of the road between Truro and Halifax. A roadkill skunk may not be very significant but it signalled to me that the fine weather we experienced for most of this winter is probably impacting the habits of many animals.
While this week’s weather has reminded us that it is still winter in Nova Scotia the fact that skunks are beginning to move about indicates that the weather is impacting their behaviour. Many animals follow a seasonal rhythm that may include migration or hibernation to avoid periods of cold weather and low food. This is followed by cycles of courtship, mating and raising young.
Other cycles that govern life include things such as the tidal cycle and phases of the moon. Some barnacles that live in tidal areas have a biological clock that operates on a tidal cycle. They feed during high tides and are inactive during low tide.
The time is changing thus weekend and it will have an impact on our bodily rhythm – at least for the time it takes for our bodies to become adjusted to it. The concept of daylight savings time was developed over 100 years ago. Basically it moves an hour of daylight from the morning to the evening. While we’ve had over 100 years to get used to it, making the adjustment twice a year is still stressful for many people. There is no doubt that it takes some time for our bodies to make the adjustment. Now that I am retired, losing an hour’s sleep isn’t as important as it once was but it still takes me a few days to get used to it.
It is well known that varying our regular pattern of sleep may have a large effect on us. All organisms, from plants and animals to bacteria and fungi, have a natural rhythm that governs their lives. This ranges from a daily cycle to longer periods that may range from weeks to years. The daily cycle is often referred to as a circadian rhythm from the Latin Circa, for around or approximately, and Diem or day. Most circadian rhythms operate on approximately a 24-hour cycle which probably explains why our clock has 24 hours. These daily cycles operate even when animals are kept in the dark and don’t have access to the usual cues we use such as sunrise and sunset.
While our circadian rhythm operates on a 24-hour schedule there are other rhythms important to life which operate on different schedules. Often referred to as a biological clock these refer to mechanisms that control various aspects of the lives of plants and animals that change over periods of time ranging from daily to seasonally or yearly.
On a broader scale we all operate on a biological clock that controls our lives from when we are born through youth, midlife and old age. While there are a few things we can do to slow down the passage of time, our biological clock continues to tick.
Some animals have cycles that may take years to take place. In the case of insects, cicadas are the champions. Depending on the species they may spend from two to 17 years in the ground before emerging to resume their life cycle. They make a one-hour change in our daily schedule look pretty simple in comparison. So, don’t forget to move your clocks ahead and get outdoors to enjoy that extra hour of daylight.
Don MacLean is an outdoor writer and biologist who lives in Pictou County.