Hedgehog Conservation: Ecology, Decline and Garden Action

West European Hedgehog (Erinaceus europaeus): Conservation and Welfare

The hedgehog is one of Britain's most beloved mammals — yet its population has declined catastrophically over the past 70 years, from an estimated 30 million in the 1950s to approximately 900,000 today (a decline of >95%). Urban populations are now declining at approximately 4–5% per year, and rural populations even faster. The hedgehog is now classified as Vulnerable to extinction in Great Britain — a serious conservation status for a once-common species.

Ecology and Life History

Diet: Insectivore — earthworms, beetles, caterpillars, slugs, millipedes. Requires abundant invertebrate prey
Range: Forages over 1–2km per night across multiple gardens and greenspaces
Hibernation: October/November – March/April (temperature-dependent)
Breeding: 2 litters possible per year; 4–5 hoglets per litter; second litter (September) hoglets often too small to survive hibernation
Lifespan: 2–5 years in wild; main mortality from road traffic, strimming, and predation during hibernation

Causes of Decline

Agricultural Intensification

Loss of rough grassland, hedgerows, and mixed farmland habitat
Pesticide use reducing invertebrate prey populations
Loss of permanent pasture removing foraging habitat

Urban Habitat Changes

Fenced, solid-boundary gardens preventing hedgehog movement between territories
Loss of invertebrate-rich habitats (decking, artificial grass, paving over gardens)
Road traffic — a major mortality cause in suburban areas
Strimmers and lawnmowers injuring hedgehogs resting in vegetation
Garden ponds and slug pellets (metaldehyde toxicity)

Badger Predation

Badgers are the hedgehog's primary natural predator — the only UK predator that can open a rolled hedgehog. In areas with high badger density, hedgehog populations are often lower. The relationship is complex — both species occupy similar niches and compete for invertebrate prey. Badger management policy intersects with hedgehog conservation in complex ways.

Conservation Actions: What Gardens Can Do

Connectivity

Hedgehog highways: 13cm × 13cm gap in garden fencing or walls allows hedgehog passage. The Hedgehog Street campaign has facilitated creation of 100,000+ highway holes
Connect neighbouring gardens to create sufficient foraging range

Habitat

Create log piles, compost heaps, and leaf piles — nesting and invertebrate habitat
Leave areas of rough grass and wild flower planting — increases invertebrate abundance
Provide hedgehog house for nesting (wooden box, partially buried, sheltered)

Food and Water

Provide water in shallow dish during dry weather
Supplementary feeding (meat-based cat or dog food, hedgehog food) supports hedgehogs — particularly late summer hoglets
Never give milk or bread — causes severe digestive distress

Garden Hazards to Remove

Check before strimming and mowing — use foot shuffling approach
Cover or drain pond exits (hedgehogs can swim but may drown if unable to exit)
Replace slug pellets with ferric phosphate products or physical barriers
Cover drains and netting

Finding an Injured Hedgehog

A hedgehog active in daylight is usually in trouble — contact a wildlife rehabilitator immediately. Signs of distress: staggering, being mobbed by flies, obvious injury, very small size in autumn.