December 2023

At 7 pm on 10th November, the temperature outside was 6.6° Celsius. It was pitch dark since before 5pm. Next morning it was 2°C. at 08:00 h. Frost decorated both garden and car. In New Zealand, folk were experiencing daytime temperatures of c. 23° Celsius. Their days are lengthening and warming and ours shortening and cooling as the globe tilts them further south towards the sun. Winter is surely upon us. Also, we are experiencing low pressure fronts swinging in from the Atlantic Ocean across these islands and giving us a frequent drenching. All this affects the living natural world in many ways. Humans are part of this, and many homes have been flooded already in parts of these islands. Homes of animals will have flooded too. Hibernating hedgehogs and lizards will have been disturbed. Many invertebrates will have drowned and be washed away as they hibernate for winter. Most birds will have been able to fly to dryer areas, but will desperately look for food in new places to keep their tiny bodies warm through metabolic heat generation.

Fundamentally, there are 2 types of animals when it comes to keeping warm. These are 1. Endothermic animals like us and most other mammals, who keep their bodies warm by eating and ‘burning’ calories to maintain body temperature as we do at c. 36.8° Celsius. The body temperature of other endothermic animals may be different, for example, many birds maintain a temperature of around 40° C. The other type are 2. the poikilothermic (or exothermic) animals, whose body temperature is regulated by the external temperature. These are the invertebrates and primitive vertebrates such as fish, amphibians and most reptiles.

Animals that hibernate allow their body temperature to drop and fall into a kind of sleep, more accurately described as suspended animation, this includes some mammals such as dormice (dormir, French for to sleep). There are many dormice within the countryside around Uckfield. I used to monitor them in Lake Wood for many years. Even when they are sleeping, they sometimes squeak if they are disturbed, and can also be heard to snore on occasion. I know of no birds that hibernate, these little feathered animals must find extra food to keep them warm in winter. That is where we can assist by providing feeders and water in our gardens.