Last week I bumped into our resident hedgehog in the garden. At the time the weather was mild as it had been throughout November. The hedgehog was very sluggish and looked like he was just about to go into hibernation. Since then the weather has become much colder and we haven’t seen him out and about. I like to think it was Hagrid, the hedgehog we rescued during the cold snap last winter, but there is no way of knowing for sure.
The hedgehog uses hibernation as its strategy to survive the cold months of winter. During the autumn it spends a lot of time and effort constructing a nest in which to hibernate. This is made of grass stems, twigs and leaves. It can be located at the base of a hedge, under a pile of logs or under a garden shed. During hibernation their body temperature drops from 340C to the temperature of its surroundings. Its heart-beat drops from 150-190 beats per minute to 20 beats per minute.
This year, I found the nest in which he is hibernating. It looks like a big ball of leaves, slightly bigger than a basketball. The spot that he chose to build this nest could not be better. It is located between the back of the garden shed and a double hedge so it is sheltered from the wind. At the base of this hedge there is an old blue plastic sand box in the shape of a boat. The nest is tucked in beneath the up-turned sand box, completely sheltered from the rain. There is a large maple tree nearby and there are lots of large dead maple leaves on the ground. The nest is made up of grasses and these maple leaves. He should be nice and snug in this well chosen site throughout this coming winter.
Over the winter, the hedgehog becomes torpid and uses very little energy. It takes a breath every six seconds and its body temperature and heart rate drop significantly. By the end of the winter it may have lost as much as a third of its body weight. This is a necessary reaction to cold weather because its usual food is not available during very cold weather. Hedgehogs feed on worms, slugs, beetles, caterpillars and insects. These disappear during the winter so hibernation is about the only strategy open to it.
Hedgehogs will eat the eggs of ground nesting birds. This became a real problem on the Hebrides a few years ago. Back in 1974, four hedgehogs were introduced to one of the islands to control slugs and snails. These hedgehogs went forth and multiplied such that, by 2002 there were 5,000 hedgehogs on Uist and Benbecula. There was a controversial plan to cull all these hedgehogs but after public outcry, it was decided to relocate them to mainland Scotland.
The biggest threat to our hedgehogs is road traffic. The hedgehogs defence when threatened is to roll into a ball but this does not work with fast moving traffic. Hedgehogs are prone to falling into the cavities beneath cattle grids. A simple ramp on one side will allow hedgehogs to climb out of these traps. Hedgehogs may also be poisoned by eating slugs which have just eaten slug pellets. So, avoid slug pellets and leave some wild areas in your garden, possibly with an old log pile. Be careful when tidying up your compost heap and check for hedgehogs before you disturb a wood pile.