Long-eared Hedgehog

Nov 9

Hemiechinus auritus

The ears of the long-eared hedgehog — longer than half the length of its head — are much larger than those of other hedgehogs. It lives in deserts and steps, using its astute hearing (and smell) to track down food, and its ample ears to radiate heat, staying cool in its sweltering home.

You're probably familiar with hedgehogs; small woodland creatures that amble through the undergrowth, stepping with little bare paws, their rotund spiky bodies swaying from side to side, long snouts, glistening black eyes, and small rounded ears. This is an apt description of the common hedgehog (Erinaceus europaeus), also known as the European hedgehog because that's where it lives, and other woodland hedgehogs (in the genus Erinaceus). However, there are some 17 species of hedgehog living throughout Europe, Africa, and Asia, many of which diverge from the presumed norm.

Elfin Hog

The long-eared hedgehog is one such critter. From head to rear, it measures between 16 and 28 cm (6.3 - 11 in), with a little tail, barely visible, at the end. Its fur is of a sandy or rusty colour, usually with a much lighter underbelly and it wears no dark mask over its face, departing from the style of many other hedgehogs. Its back is covered in the quintessential hedgehog spines, each one patterned in alternating shades of light and dark. This landscape of little spears is embedded in a unique kind of muscle sheath, allowing the hedgehog to curl up and hide all the soft, vulnerable parts of its body while erecting all the sharp bits.

And then there's this hedgehog's defining trait. Unlike most other hedgehogs, whose little rounded ears are often overshadowed by their abutting spines, those of the long-eared hedgehog are extremely noticeable. Long, wide, and slightly pointy, its ears stand well above its spines — reaching lengths of up to 6 cm (2.4 in) or more than half the length of its head (if folded forward, the ears cover its eyes) — and are readily manoeuvred about like motorised satellite dishes in search of a signal.

Desert Denizen

The long-eared hedgehog foregoes the green forests, grassy meadows, and bountiful pastures of its woodland cousins. Instead, it lives in arid deserts and dry steppes littered with xeric bushes and sun-baked rocks. In the west, it ranges from Egypt in Africa and the edge of Ukraine in Europe, stretching east over a part of Russia, into the Middle East, Central Asia, and all the way to China and Mongolia. To survive in its harsh home, it either finds shelter or makes its own. Often, it digs a burrow; usually below the cover of a small bush, with a single opening and a typical length of about 45 cm (17.7 in), but some abodes can be up to 150 cm (59 in) long. Sometimes it acquires a burrow already dug by another small animal, like the unfortunately (but appropriately) named fat sand rat (Psammomys obesus). Or — if it's a particularly lazy individual — the hedgehog may just find a ditch to rest in or some rocks to hide under.

Over parts of its range, rainfall brings 400mm (16 in) of water per year, dampening and enlivening the dry soil. In other parts, only 100mm falls annually, well below the threshold — 250 mm (10 in) — that constitutes a desert. And so, it's a good thing this hedgehog handles scarcity well. In a laboratory setting (which granted, does not reflect the conditions of a desert) the long-eared hedgehog was able to survive for as long as 10 weeks with no food and no water — a statistic with some probable cruelty behind it (if they let the hedgehog die to find its ultimate limit, or eventually fed and watered it, I don't know).

In the wild, it is unlikely to go that long without food at least. It is a hunter with proficient senses. As expected, its hearing is acute, and it's also aided by its black-button nose which bestows a sharp sense of smell. It emerges from its burrow at night to trek across dunes and scurry atop gravel, travelling up to 9 km (5.6 miles) in one night. It tracks down leaping grasshoppers, crawling beetles, and swarming termites. While insects and other invertebrates are its primary prey, it'll occasionally eat fruits and vegetables, as well as lizards and snakes. It's even known to face down scorpions, kill them, and feast on their soft insides.

Toxins and Spikes

Many hedgehogs around the world battle venomous foes and have thus developed a natural resistance to certain venoms — not an immunity, a high enough dose will still end a hedgehog, but at least a high tolerance. A known example is the desert hedgehog. Like the long-eared species, this critter eeks out a living in a land of unyielding aridity and heat; found in North Africa, Sudan, and the Arabian Peninsula. With sparse choice in the desert, the desert hedgehog must take what prey it can get, even if that prey is venomous. It is aided by a resistance to snake and insect venoms; its tolerance is estimated to be 30 to 40 times higher than that of a rodent of similar size.

Such a natural ability — akin to a permanent "potion of poison resistance" — is surely useful for a hedgehog trying to get its teeth on prey with a toxic stinger or venomous fangs, which often involves exposing the vulnerable parts of its body. But when it comes to defence, the hedgehog probably prefers not to test the limits of its toxin tolerance, and besides, it has a back covered in armaments for a reason. These spines are actually modified, hollow hairs made of the protein called keratin; i.e. the stuff that makes up your own hair and nails (hard keratin), as well as the outer layer of your skin (soft keratin). This versatile protein is used throughout the animal kingdom to make structures ranging from the hair and fur of mammals, as well as horns and even "scales" (in the pangolin), to the outer layer of reptile scales and turtle scutes, and the feathers of birds.¹

In hedgehogs, keratinized spines are famously employed as a defensive tactic. When under duress, a hedgehog uses its belly and back muscles to tuck all of its soft parts (head, legs, tail) under itself, as it curls up into a ball. All that's left exposed are the now-erect spines; appearing like a globe of crisscrossing spikes. In most cases, this serves as a more than adequate defence against predators, venomous or not. The spines of the desert hedgehog are especially long, creating an even larger "area of pain" around its body for any overeager predator that tries to eat it. While the long-eared hedgehog also curls into a spiky fortress for defence, it often lacks the patience for that kind of siege. When faced with a threat, it is, more than any other hedgehog, prone to just make a run for it — a surprisingly fast sprint — or even run towards the predator; turning the tables by becoming the threat, leaping at its aggressor, and trying to stab it with its short spines.²

Hibernating Hedgehogs

The long-eared hedgehog isn't stupid — it's at least smart enough to still exist, despite its penchant for aggressively lunging at predators. It doesn't live in such harsh conditions just for the fun of it, or for an extra challenge. It has found its niche in a hellish kind of landscape, but it's pragmatic. It has to be or else it wouldn't survive. It's known to make use of desert oases and exploit the enterprises of humans — parks and gardens, cultivated fields and olive groves; they all make for good living compared to the barren desert. It prefers to stay in areas with as much vegetation as possible and, as far as possible, it tries to avoid the hottest of deserts or the coldest of mountains. But despite its best efforts, it must still be ready to deal with searing heat and survive the stinging cold.

When temperatures swelter, this hedgehog's substantial ears fan out and radiate its body heat, allowing it to cool down slightly. Otherwise, its response to inhospitable temperatures is much the same for both extremes (hot or cold); it crawls into its burrow and stays there. It doesn't just sleep that time away, it has the ability to enter torpor, slowing its bodily systems to minimize the amount of energy it uses — decreasing its heart rate, slowing its breathing, and less strictly regulating its body temperature (allowing it to fluctuate within 1 - 2 °C of the surrounding temperature). Torpor differs from hibernation in that these periods of inactivity are usually quite short, lasting between a few hours and about a day. It also allows the hedgehog to react quickly to a changing environment, as it can enter torpor during any season and in response to events like droughts, heat waves, and cold spells, or even arouse itself quickly in response to more active dangers. To be ready for potentially long periods without food, it stocks up. But instead of stashing meals in its underground shelter like a doomsday prepper, it stores the calories on its body as fat — usually gorging on insects during spring when they're more plentiful.

This is even more essential for the long-eared hedgehogs that live in colder climes, for they must prepare for true hibernation. In North Africa, hibernation can be anywhere from a brief 5 days to a longer 40. In Pakistan and northern India, where fridged winds tear through mountainous landscapes and winter can bring temperatures of -6°C (21°F), hibernation can last between 3 and 6 months — interspersed with periodical intervals of activity. In such conditions, the body temperature of the hedgehog itself can approach 0°C (32°F), as it tries to conserve all the energy it has stored up.

Hoglets

Typically, a long-eared hedgehog burrow is a bachelor pad (or bachelorette pad), suitable for a solitary hedgehog. Of course, males and females have to be willing to meet, and they do. After a brief (and romantic?) session of sniffing, licking and rubbing, a couple will copulate. There, their relationship is terminated — neither he nor she invites the other back to their burrow. Instead, the pregnant mother commences on a new construction project; creating a subterranean home in which she'll birth and care for her litter of hoglets. Once she gives birth, to between one and four young, she gives her newborns a salivary bath by licking them clean. In times of shortage, females of the aforementioned desert hedgehog have been known to cannibalize their own young — for the long-eared hedgehog, this hasn't been observed in the wild, but in captivity, the species does, quote; "show a tendency toward cannibalism".

The hoglets are born blind and naked, except for a smattering of spines — which, thankfully for the mother, are very soft. During their time with mom, their eyes open (after a week or two), solid teeth grow in (after about 23 days), and soon they switch to a diet of solid food. But before any of this happens, they start to grow in their defences — their little backs sprout with spines, quadrupling in length only five hours after birth, and by two weeks, the spines are fully grown. After 30 to 40 days, the hoglets leave their mother. They are ready to face the world; treading deserts hot and cold, twitching big ears in search of crunchy prey, and boldly jumping spikes-first at danger.

From top left; pangolin scales, a whale’s baleen plate, macaw feathers, deer hooves, and crocodile scales.

¹ Whether keratin is hard or soft depends on the level of cystine (an amino acid) it contains — this is not to be confused with alpha [a] and beta [β] keratin; mammals only produce a-keratins, while birds and reptiles produce both.

Keratin is used in the making of the fur and hair of mammals, as well as their sharp claws, sturdy hooves, and horns — even the scales of pangolins, which overlap to create their armour, and the baleen plates of whales (their krill-filtering "teeth"). Like us, with our keratinized outer layer of skin, reptiles are covered in keratin. Theirs, however, is a hard and watertight armour of scales. In turtles, those multi-shaped plates that cover their bony shells like jigsaw pieces, called 'scutes', are also made of keratin. Keratin gives birds the ability to fly; their feathers are made up of the more durable β-keratin. The same is true of their scaly legs, claws, and the outer shell of their beaks. You could set up an entire art gallery to exhibit all the multifaceted forms and patterns that are made from keratin.

New World porcupines on top — a North American porcupine (*Erethizon dorsatum*) and Prehensile-tailed porcupine (*Coendou prehensilis*) — and Old World porcupines on the bottom — Malayan porcupine (*Hystrix brachyura*) and Cape porcupine (*Hystrix africaeaustralis*).

² The long-eared hedgehog’s aggressive defence is somewhat similar to that of the famous quilled rodents; the porcupines. Despite sharing a back covered in spines, porcupines and hedgehogs are not closely related to one another — in fact, the porcupines themselves consist of two groups, the New World porcupines in the Americas (in the family Erethizontidae) and the Old World porcupines in southern Europe, Africa, and Asia (in the family Hystricidae). Both groups are rodents, but quite unrelated to one another. While hedgehogs are in the order Eulipotyphla, with groups like "true" shrews and moles. It turns out that, on the matter of spines or quills, all three groups — hedgehogs, New World porcupines, and Old World porcupines — all evolved their spiky defences independently from one another — a salient case of convergent evolution.

Having evolved independently, their spines/quills differ in several ways. One example is how firmly rooted they are; porcupines can famously detach their quills (not shoot them, but ram them into the victim), leaving them embedded in a predator's skin. While the spines of hedgehogs are pretty deeply rooted (apparently you can hold up a hedgehog by a single quill, although that sounds painful and cruel, so maybe don't). Hedgehogs do shed their spines, losing and replacing about 90% of them throughout their lifetimes, doing so in large quantities when they're younger in a process referred to as "quilling".

**Where Does It Live?**

⛰️ Dry steppes, semi-deserts, and deserts.
📍 North Africa, the Middle East, and Central Asia.

‘Least Concern’ as of 11 September, 2016.

IUCN

Size // Small
Length // 160 - 278 mm (6.3 - 11 in) , tail 10 - 55 mm (0.4 - 2.2 in)
Weight // 230 - 400 g (8.1 - 14.1 oz), and up to 1 kg (35 oz / 2.2 lbs)
Activity: Nocturnal 🌙
Lifestyle: Solitary 👤
Lifespan: 7 years on average
Diet: Omnivore
Favourite Food: Insects and worms 🦗
Class: Mammalia
Order: Eulipotyphla
Family: Erinaceidae
Genus: Hemiechinus
Species: H. auritus

From front to end the long-eared hedgehog measures between 16 and 28 cm (6.3 - 11 in) — similar in size to a common European hedgehog. But unlike its cousins, this hedgehog's eponymous ears reach lengths of up to 6 cm (2.4 in).

It uses its large ears to radiate body heat and cool itself down.

It lives in semi-deserts, deserts, and dry steppes; ranging from Egypt, through the Middle East, and into Central Asia.

It takes shelter in a burrow; usually a simple dwelling with a single opening, found beneath a bush, and running some 45 cm (17.7 in) beneath the ground — although some burrows can be up to 150 cm (59 in) long.

This hedgehog may either dig its own burrow or borrow one from another small burrowing animal, such as a fat sand rat.

When conditions get extreme (too hot, cold, or dry) this hedgehog can enter a state of torpor; decreasing its heart rate, slowing its breathing, and allowing its body temperature to fluctuate within 1 - 2 °C of the ambient temperature.

In laboratory conditions, the long-eared hedgehog was able to survive for as long as 10 weeks with no food and no water.

In the wild, it can travel up to 9 km (5.6 miles) per night in search of crickets, beetles, and termites, small lizards and snakes, and fruits and veggies.

This hedgehog is known to hunt, kill, and eat venomous scorpions and, likely as a result, has developed a natural resistance to certain venoms (although a high enough dose will still kill it).

Like other hedgehogs, the long-eared has a natural threat response — curling up into a tight ball with only its spines exposed — but this species tends to be more feisty than others. Sometimes, it's known to just run from a predator (surprisingly quickly), rather than wait it out, alternately, it might run towards the threat and jump at it with its sharp spines.

Hoglets are born blind and naked, save for a smattering of soft spines. But only five hours after birth, their spines quadruple in length, and by two weeks, they are fully grown.