Grizzly Bear
⚡ Key Facts & Quick Answers (AEO Summary)
- Taxonomic Class: Mammals
- Dietary Niche: Omnivore
- Max Speed: 56 km/h (35 mph)
- Adult Weight: 130 - 360 kg (300 - 800 lbs)
- Typical Lifespan: 20 - 25 years
- Primary Habitat: Temperate forests, alpine meadows, tundra
- Native Region: North America
- IUCN Red List: Least Concern
📊 Physical & Biological Metrics
🧬 Scientific Taxonomy & Biological Classification
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Mammalia |
| Order | Carnivora |
| Family | Felidae |
| Genus | Ursus |
| Species Binomial | Ursus arctos horribilis |
📖 1. Species Overview
The grizzly bear, a subspecies of the brown bear, is a powerful apex predator native to North America. Known for their massive size, shoulder hump of muscle, and long claws, grizzlies are highly adaptable omnivores. They play a vital role in forest ecosystems by distributing seeds and aerating the soil while digging. Grizzlies are famous for their seasonal hibernation, spending up to 7 months asleep in winter dens.
🦿 2. Physical Appearance, Anatomy & Adaptations
Grizzlies have thick shaggy fur that ranges from blonde to dark brown, often with silver-tipped guard hairs that give them a 'grizzled' look. They are easily distinguished from black bears by a large hump of muscle on their shoulders, which provides power for digging. They have a concave 'dished' face and claws that can reach 4 inches long. Adult males weigh 200 to 360 kg, while females weigh 130 to 200 kg.
🗺️ 3. Habitat, Geographic Distribution & Territorial Range
They inhabit dense forests, subalpine meadows, coastal areas, and open tundra. Grizzlies are solitary animals, except during the salmon spawning season when many bears gather at rivers. They are territorial and use scent scratching on trees to communicate. During autumn, they enter hyperphagia—a state of intense eating—to pack on fat before digging a winter den in a hillside to hibernate.
🥩 4. Diet, Feeding Strategy & Hunting Tactics
Grizzlies are omnivores with a highly varied diet. They eat roots, berries, nuts, insects, fungi, and grasses. They also hunt rodents, deer, elk, and moose calves. In coastal areas, they feed extensively on spawning salmon, which provides crucial fat for winter survival. They use their long claws and powerful shoulder muscles to dig up roots and ground squirrel burrows.
🐣 5. Reproduction, Lifecycle & Social Hierarchy
Mating occurs between May and July. However, grizzlies practice delayed implantation, meaning the embryo does not attach to the womb until the female enters her winter den in autumn. Gestation lasts about 180 to 250 days, and the female gives birth to 1 to 3 tiny, blind cubs inside the den in January or February. Cubs nurse on rich milk and emerge in spring. They stay with their mother for 2 to 3 years.
🛡️ 6. Conservation Status, Population Threats & Protection
Grizzlies are listed as Least Concern globally, but are protected as Threatened in the contiguous United States, where their range has been reduced by 98%. Primary threats include habitat loss due to logging, mining, and human settlement, and conflicts with humans (bears attracted to garbage or livestock). Conservation efforts focus on protecting wild spaces and installing bear-resistant food storage.
💡 Fascinating Facts & Trivia
- The hump on a grizzly's back is actually a solid mass of muscle used for digging up roots and building dens.
- Grizzlies can run up to 56 km/h (35 mph), which is faster than Olympic sprinters.
- During hibernation, they do not eat, drink, urinate, or defecate for up to seven months.
- They have an extraordinary sense of smell, estimated to be 7 times stronger than a bloodhound's.
❓ Frequently Asked Questions (FAQ)
Direct authoritative answers regarding the biology, feeding habits, and habitat of the Grizzly Bear.
The Grizzly Bear is scientifically classified as Ursus arctos horribilis. It belongs to the genus Ursus within the family Felidae, class Mammalia, and phylum Chordata.
In the wild, Grizzly Bears inhabit Temperate forests, alpine meadows, tundra. Their native geographic range primarily spans North America.
The Grizzly Bear is classified as a Omnivore. It feeds primarily on specialized nutrients suited to its ecological niche in Temperate forests, alpine meadows, tundra.
A Grizzly Bear can achieve top speeds of 56 km/h (35 mph) and weighs approximately 130 - 360 kg (300 - 800 lbs). Its expected natural lifespan is 20 - 25 years.
The Grizzly Bear (Ursus arctos horribilis) is currently designated as Least Concern on the IUCN Red List of Threatened Species.
Cite this Article
FaunaWiki Zoological Database (2026). "Grizzly Bear (Ursus arctos horribilis) Species Profile."
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