Nature on our doorsteps: Sleeping away the winter chill
The only animals that truly hibernate in Ireland are bats and hedgehogs.
As winter arrives, these creatures drop their heart rate and body temperature. This causes them to go into a deep, coma-like sleep.
While these mammals can sleep like this for several months, they sometimes wake up during periods of milder weather.
Waking up, however, uses vital fat reserves. Unfortunately, as they are unlikely to find enough food in wintertime to replace the fat, this energy is wasted.
Even if they go back to sleep again, their remaining fat reserves may not last until springtime.
Squirrels do not hibernate for the whole winter. During particularly cold or wet weather they can sleep for a few days. When conditions improve again, they will search out the acorns and hazel nuts that they stashed away in autumn.
Queen bumblebees, flies, ladybirds, and butterflies like the Peacock and Small Tortoiseshell enter a state of ‘suspended animation’ in wintertime, sleeping in sheltered locations out of the weather.
Snails will also shut down for winter, sealing the opening of their shell with a layer of mucous which hardens to protect them until springtime.
Even humans like to slow down and stay cosy during winter, and maybe even to sleep just a little longer in the darker mornings.
By Rosaleen Dwyer.