Amur Hedgehog (Erinaceus amurens)

The Amur hedgehog (Erinaceus amurensis) belongs to the order Eulipotyphla and the family Erinaceidae. It inhabits the temperate forests, forest‑steppe mosaics, and shrublands of the Russian Far East (Primorsky Krai, Khabarovsk, Amur Oblast), northeastern China (Heilongjiang, Jilin), and the Korean Peninsula. This medium‑sized hedgehog is characterized by a coat of sharp spines covering its back, a short snout, and a keen sense of smell. It is primarily nocturnal and solitary, retreating to burrows or dense leaf litter during daylight. The species prefers mixed broadleaf‑conifer forests with abundant ground cover, which provide both shelter and a rich supply of invertebrate prey. Although the IUCN classifies the Amur hedgehog as Least Concern, localized pressures such as habitat conversion, road mortality, and pesticide use have caused population declines in some peripheral areas. Conservation actions focus on preserving forest corridors, monitoring roadkill hotspots, and promoting pesticide‑free farming near key habitats.

Amur hedgehogs are solitary for most of the year, establishing individual home ranges that average 0.5–1.5 hectares depending on habitat quality. They are strictly nocturnal, emerging at dusk to forage and returning to a nest or burrow before sunrise. Territorial boundaries are marked with scent glands located on the flanks, and individuals may emit low grunts or hisses when threatened. Home ranges overlap minimally, but temporary tolerance occurs during the brief breeding season. Hedgehogs are excellent diggers, creating shallow burrows for shelter and nesting. Their activity peaks in spring and autumn when invertebrate prey is abundant, while summer heat may reduce foraging time. Seasonal migrations are rare, but individuals may shift microhabitat use in response to food availability and temperature fluctuations.

The Amur hedgehog is an opportunistic omnivore with a strong insectivorous bias. Its diet consists of 60–80% invertebrates, including beetles, caterpillars, earthworms, slugs, and snails, supplemented by 15–25% plant material such as berries, seeds, and fallen fruits. Small vertebrates like amphibians and lizards are taken occasionally, especially during the breeding season when protein demand rises. Hedgehogs forage on the forest floor, using their keen sense of smell to locate prey hidden under leaf litter or within soil. Seasonal shifts occur: spring diets are rich in earthworms and newly emerged insects, while autumn sees increased consumption of fallen fruits and nuts to build fat reserves for winter torpor. An adult hedgehog consumes roughly 5–10% of its body weight per night, adjusting intake based on temperature and food availability.

Sexual maturity is reached at 8–10 months for both sexes, though females often breed for the first time in their second year. The breeding season extends from late April to early July, triggered by increasing day length and temperature. After a gestation period of approximately 35 days, females give birth to litters of 3–6 hoglets, each weighing about 30–40 grams at emergence. The young are born hairless and blind, developing spines after 10–12 days. Mothers provide exclusive care for 4–5 weeks, during which they nurse the hoglets and teach them foraging techniques. By six weeks, juveniles are weaned and begin independent foraging, though they may remain within the maternal home range for several months before dispersing to establish their own territories.

The IUCN lists the Amur hedgehog as Least Concern, yet several localized threats jeopardize its long‑term viability. Habitat loss from logging, agricultural expansion, and urban development fragments the forest‑steppe mosaics essential for foraging and nesting. Road networks intersect key habitats, leading to an estimated 5–10% increase in mortality in heavily trafficked areas. Pesticide and rodenticide use reduces invertebrate prey abundance and can cause secondary poisoning. Illegal capture for the pet trade, though not widespread, adds pressure in border regions. Climate change may alter the phenology of insect prey, potentially creating mismatches between food availability and reproductive timing. Conservation measures include protecting contiguous forest blocks, installing wildlife crossing structures, and promoting integrated pest management to maintain a healthy invertebrate base.

• The Amur hedgehog can roll into a tight ball, exposing only its spines, as a defense against predators.
• It can enter a state of torpor during harsh winter nights, reducing its metabolic rate by up to 70%.
• Unlike some hedgehog species, the Amur hedgehog has a relatively long breeding season that can produce two litters in a single year under optimal conditions.
• Its spines are made of keratin and are not shed; they grow continuously and are replaced as they wear down.
• The species plays a crucial role in controlling insect populations, especially agricultural pests like cutworms and beetle larvae.