Gary is POTG's resident European hedgehog — and hedgehogs are full of surprises!
Hedgehogs are small, spiny mammals belonging to the family Erinaceidae — which makes them distant cousins of moles and shrews, not porcupines or rodents. Their spines are made of keratin — the same material as your hair and fingernails. Unlike porcupines, hedgehogs cannot shoot their spines.
When danger approaches, hedgehogs curl into a tight ball using a special muscle called the paniculus. This muscle runs along their back like a drawstring, pulling their skin (and all those spines) tightly around them. Only very strong predators like badgers can force them open.
Hedgehogs are insectivores — their main diet is insects, worms, snails, beetles, and caterpillars. They are actually omnivores though, and will also eat mushrooms, baby mice, and even eggs they find on the ground. In dry desert regions, some hedgehog species can eat scorpions and snakes!
Using their long, sensitive snouts, hedgehogs snuffle through leaf litter and undergrowth in the dark, relying almost entirely on their excellent sense of smell to find dinner. They have 44 teeth — including sharp premolars designed for crunching hard beetle shells.
Gary (as a European hedgehog) is one of only three British mammals that hibernate — the others are bats and dormice. In late autumn, hedgehogs build a warm nest from leaves, grass, and twigs, then curl up for up to 5 months.
During hibernation their body temperature drops from 35°C to just 2-5°C, their breathing slows dramatically, and their heart rate drops from around 190 beats per minute to just 20. They can survive months without eating or drinking, living off stored fat. To prepare, hedgehogs must double their weight by late autumn — they look like plump bowling balls before going in!
Hedgehogs are solitary and nocturnal. They don't live in groups or form family bonds — a group of hedgehogs is called a "prickle" or "array," but you'll almost never see one, because they avoid each other. Males and females only come together briefly in spring to mate; the female raises her young (called hoglets) entirely alone.
Hedgehog eyesight is poor — their eyes are adapted for detecting movement in dim light, seeing mostly in shades of grey. Instead, they rely on smell and hearing. Remarkably, hedgehogs can hear in the ultrasonic range, picking up insect noises even from within the grass or soil. Their large, mobile ears are constantly scanning for danger.
Hedgehogs communicate through body language: spines flat = relaxed, spines up + freeze = alert, curl into ball = full defence. When relaxed and happy, they sometimes make small sighing sounds or even snore gently.
Despite their spines, hedgehogs do have predators. Badgers are the top predator of hedgehogs in the UK — they are strong enough to force open even a perfectly curled hedgehog. Foxes may try to flip a hedgehog over to reach its unprotected belly or urinate on it to try to make it uncurl (hedgehogs are very patient and simply wait it out). Owls and other birds of prey can swoop and grab a hedgehog with their talons, aiming for the face.
The biggest threats in Britain today are human-related: habitat loss (gardens being paved over), garden fencing that prevents hedgehogs from roaming, and pesticide use which reduces the insects they eat. British hedgehog numbers have fallen by around 50% since 2000.
Test everything you've just learned — 10 questions about hedgehogs!