‘Hedgehogs’ – a talk by Pat Morris
Pat has studied hedgehogs for some 60 years and his students at Royal Holloway College, London, undertook investigations to help answer questions about them. These prickly, smelly little animals are very popular.
Hedgehogs occur in suitable habitat throughout the UK including the Isle of Man and some of the Scottish Islands. They avoid high mountain tops and wet ground. As they are mainly nocturnal, check for their presence by looking for their little-finger sized droppings, containing many beetle remains. They are our only spiny mammal and when fully curled up head and legs are completely hidden. Hedgehogs are true hibernators and should weigh at least 450 grams (c1lb) at the start. In the autumn they have to build up their fat reserves. White fat keeps them alive during hibernation and brown fat helps them become active again. Hibernation sites include rabbit burrows, hollow trees, and under garden sheds or brambles. They gather a large pile of leaves and shuffle around until the leaves lie flat providing protection from cold, rain and snow. We are too tidy and bonfires are a potential trap. Always check carefully for a hedgehog before lighting one.
Hedgehogs range widely at night. An experiment with radio-transmitters showed that they can travel over 1km a night and males have overlapping territories, simply keeping out of each other’s way. A viable population of perhaps 32 individuals needs about 90 hectares (0.9 sq km). Pat is often asked whether it is good to feed them. It appears that they use this as supplementary food, taking some and then going on to feed naturally. Several will come to one feeding station in a night. An analysis of road-kill stomachs showed that beetles were most frequently taken followed by earwigs, caterpillars, millipedes, worms, spiders and slugs. Dead birds, eggs and chicks are also eaten which can be a problem if for example a hedgehog discovers a tern colony.
Mating is done carefully and is preceded by a lot of snorting with the male following the female around. Four to five young are born. Their initial white spines come through soon after birth. Later they acquire some 7,000 adult spines. The young become independent from about six weeks. Those that survive their first year may live to be three or more. By six years their teeth are very worn as earthworms contain a lot of grit.
We don’t know the size of the UK hedgehog population but there has undoubtedly been a considerable decline since the 1960s. Threats include:
- road traffic
- mowing machines cutting back roadside verges
- strimmers used to cut back coarse vegetation in gardens. Always check first as these machines can inflict terrible injuries.
- litter such as polystyrene cups and six-pack holders which they get caught in
- garden netting not securely fastened or left lying around
- garden ponds with steep sides and no ramp
- cattle grids with no ramp
- weedkillers, insecticides and turf enhancement chemicals which directly or indirectly reduce their food supply
- the much increased badger population. Badgers not only eat hedgehogs but are also competitors having a similar diet. One badger eats as much as five hedgehogs. An Oxford study suggested that where the badger population exceeds 13 per 10 km2 the hedgehog population is likely to become extinct
Intensive farming has driven hedgehogs from large areas of countryside leaving gardens and parks as important habitats. Pat asked us all to look out for hedgehogs. Injured or underweight hedgehogs can be taken into care at Hedgehog Rescue Centres and rehabilitated where necessary. A hole at the bottom of garden fences allows them to go from garden to garden. The Hedgehog Street website has lots of tips for making our gardens hedgehog friendly.
We thank Pat for an excellent talk about a fascinating animal which most of us will have encountered at some time. I am sure he encouraged us to make our gardens more hedgehog friendly and possibly to buy one of his books on this very attractive mammal.
Helen Baker
