Hedgehogs and Hibernation
People often see hedgehogs out and about in their gardens in the evening, but become concerned when they are still seeing them into October and beyond.
Although people need to be aware of small hedgehogs or juveniles as we call them being out and about and not gaining enough weight for winter and hibernation, we need to remember why hedgehogs hibernate before we start panicking and rescuing every one, small and large, that we see out, just because it is October.
Hedgehogs hibernate to avoid the problem of lack of food; it is pointless to waste valuable energy, endlessly searching for food in frozen ground. Instead the hedgehog retreats to his hibernaculum, (winter nest) and goes to sleep until conditions improve.
It is thought that hedgehogs hibernate from autumn through the winter until the spring, this is not so. Hedgehogs do not have the luxury of calendars; they react to the environment around them. When the temperature at ground level drops sufficiently for a prolonged period the hedgehog slips into hibernation.
In recent years this has been between January and March.
The hedgehog shuts its system down almost to a standstill, the body temperature cools, breathing and heart rate slow, in fact a hibernating hedgehog may only take a breath every four minutes or so. This ‘shutting down', enables the hedgehog to be economical with the built up fat reserves.
Hedgehogs may wake up during hibernation for short periods of activity. It must be remembered that just because a hedgehog is spotted out and about in the middle of winter it is not necessarily in difficulty.
There is increasing awareness about hibernation and the fact that a hedgehog needs to be a certain weight to survive the winter sleep and that some, which are too small, may die, but rarely is this process explained fully, so we know when to and when not to step in.
Late litters of hoglets do not always have the time to put on sufficient fat to carry them through the winter, should we in fact have a season that can be described as winter! If a hedgehog is thought to be underweight it should be weighed, 500g is an acceptable weight as we approach cold weather. Those lighter than this will have to be kept until they reach the acceptable weight and then released. But please, if the hedgehog is healthy and active, behaving naturally and foraging at night, the temperature is mild and there is a plentiful food supply, should we be picking them up at all? If temperatures are mild, those that have been taken in and have gained sufficient weight can be released throughout the autumn and early winter period, there is little point imprisoning a hedgehog in a cage for months on end, as soon as the target weight is reached, if the conditions in the wild are right, the hedgehog can be released.
Sometimes it is not clear whether a hedgehog needs to be ‘rescued' or not, or if it is appropriate to release, so seek advice and don't forget, a saucer of a good quality tinned cat or dog food and a shallow container of water will always go down well, put this out at dusk and then retire to watch!
