Brown Bear Fact File
Despite their name the brown bear may be colored cinnamon, light cream, gray, silver or almost black.
The grizzly bears of North America many have a lighter tip on their fur giving them a grizzled appearance from which their name is derived.
Sitting between the shoulders is a large hump of muscle which helps provide the strength needed to ding in their den. Further assistance with this is provided by the large claws on each foot.
Brown bears tend to be smaller in Europe and Asia compared to those in North America. The size difference is thought to be tied to diet. Larger individuals tend to eat more meat while smaller individuals feed on more vegetables.
At the end of the body is a short tail measuring between 6 and 20cm (2-8in).
Males brown bears tend to be larger than females. Adults have an average body length of between 1.7 and 3m (5.5-10ft) long with a height of 1.5m (5ft) tall. Males weigh an average of 130-550kg (287-1213lbs) while females weigh 80-250kg (175-551lbs).
Their diet is variable based on their habitat. Those which live closer to the sea or rivers tend to have more fish in their diet.
Bears help to increase the health of the ecosystem by scattering seeds of fruit in their scat. They will also stir up the soil helping to release nitrogen.
A brown bear may be capable of taking down large prey items such as caribou, moose, bison and pronghorn.
Where they live near humans bears may forage for human waster or hunt on farms.
In the US a major food source is the miller moth or army cutworm as they are known in their larval stage. Prior to hibernation bears may forage up to 40,000 per day.
They can store carrion by covering it with grass and moss. The moss helps to kill fungi and bacteria to preserve the meat.
1.7 and 3m (5.5-10ft)
Wild 25 years
Captive 40 years
— AD —
Brown bears can be found in a wide range across Asia, Europe and North America. Their range has been significantly reduced and they are extinct in many parts of their range.
Currently brown bears can be found in Afghanistan, Albania, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Bulgaria, Canada, China, Croatia, Estonia, Finland, France, Georgia, Greece, India, Iran, Islamic Republic of, Iraq, Italy, Japan, Kazakhstan, Democratic People’s Republic of Korea, Kyrgyzstan, Latvia, Mongolia, Montenegro, Nepal, North Macedonia, Norway, Pakistan, Poland, Romania, Russia, Serbia, Slovakia, Slovenia, Spain, Sweden, Tajikistan, Turkey, Ukraine, United States and Uzbekistan.
It is unclear if the species has gone extinct already in Bhutan. They are confirmed to be extinct in Algeria, Belgium, Denmark, Egypt, Germany, Hungary, Ireland, Israel, Jordan, Liechtenstein, Lithuania, Luxembourg, Mexico, Moldova, Monaco, Morocco, Netherlands, Palestine, Portugal, San Marino, Tunisia and the United Kingdom. Their current presence in Andorra, Austria, Czechia, Switzerland and Turkmenistan is uncertain.
Due to their wide range they make their home in many habitat types. These include tundra, alpine, meadows, forests, Arctic shrubland, rainforest, dry Asian steppe and more. Brown bears can adapt to the most habitats of any bear species.
Mating takes place from mid-May to July. During this time both the males and females may mate with multiple partners. Dominance appears to have little effect on access to females with lower ranked males mating as much as higher ranked animals.’
Females undergo delayed implantation and can hold off development of the eggs beginning until conditions are favorable.
The birth occurs in her den which will be lined with mosses and grasses. The birth occurs after a 6-7 month gestation period while the female is hibernating.
An average litter includes 2 cubs though up to 4 is possible. At birth the cubs have closed eyes and a sparse coat of fur. They are reliant on their mom for everything and will grow by being provided milk.
Young are weaned off milk by 1.5-2.5 years old but may remain with their mother for 3-4 years. The long period of care and high age at maturity leads to the species having the lowest reproductive rate of any land mammal in North America.
Orphaned cubs may be adopted by another female. Those that are not adopted and not older than 6 months often do not survive.
Females tend to mature earlier than males with the average age at maturity being six years old.
This species has been bred with polar bears to create a hybrid known as the grolar or pizzly bear.
Each winter brown bears enter in to a period of hibernation where they will sleep for most of the winter. This is undertaken in a den which they dig. By hibernating the bears can survive during a period where food is scarcely available. Females tend to spend longer in the den with males.
Dens can be built in a range of locations including tunnels in the earth, rocky mountains, rock cavities, under tree roots or under shrubs.
During their hibernation they will not pee or poop, they are the only mammal species to do this.
Brown bears are primarily solitary but will come together where there is an abundance of food such as during the annual salmon run.
North American animals tend to be active during the day while their European counterparts who often live close to humans live a more nocturnal lifestyle.
They have a social hierarchy with males being most dominant followed by females with cubs and then the single females are last. Females with cubs may challenge the male though. Males spend large amounts of their time fighting to establish dominance.
Predators and Threats
Browns bear are the apex predator in much of their range with no natural predators. In Siberia rare attacks by Amur tigers on brown bears have been recorded.
Humans present the main threat primarily through habitat destruction and hunting.
Brown bears are often persecuted to a common misconception that the attack humans. This is a rare occurrence and most often is a result of a human standing between a mother and her cubs.
14 subspecies of brown bear are recognized worldwide such as the grizzly bear of North America. The largest subspecies is the Kodiak bear from North America while the smallest is the Eurasian brown bear from Europe.
Scientists continue to debate if these represent full subspecies or just size differences based on food availability.
A brown bear is featured on the state flag of California despite the species having gone extinct there in 1922.
A male bear is a called a boar, the female a sow and the young are known as cubs.
Public Domain/ USFWS or US NPS
Burnie, D., 2011. Animal. 3rd ed. London: DK
Jackson, T.,2011. The Illustrated Encyclopedia of Animals, Birds & Fish of North America. 1st ed. Leicestershire: Lorenz Books
Martin, R., Bryan, K., Cooper, D. and Bond, S., n.d. The Animal Book. Lonely Planet.
Brown Bear (Ursus arctos) Fact Sheet. c2010-2019. San Diego (CA): San Diego Zoo Global; [accessed 22 February 2021]. http://ielc.libguides.com/sdzg/factsheets/ brownbear.
Animals.sandiegozoo.org. 2021. Brown Bear | San Diego Zoo Animals & Plants. [online] Available at: <https://animals.sandiegozoo.org/animals/brown-bear> [Accessed 22 February 2021].
The Nature Conservancy. 2021. Brown Bear. [online] Available at: <https://www.nature.org/en-us/get-involved/how-to-help/animals-we-protect/brown-bear/> [Accessed 22 February 2021].
Helmenstine, Anne Marie, Ph.D. “Brown Bear Facts (Ursus arctos).” ThoughtCo. https://www.thoughtco.com/brown-bear-facts-4175063 (accessed February 21, 2021)
Baltimore, T., 2021. Brown Bear | The Maryland Zoo. [online] The Maryland Zoo. Available at: <https://www.marylandzoo.org/animal/brown-bear/> [Accessed 22 February 2021].
McLellan, B.N., Proctor, M.F., Huber, D. & Michel, S. 2017. Ursus arctos (amended version of 2017 assessment). The IUCN Red List of Threatened Species 2017: e.T41688A121229971. https://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T41688A121229971.en. Downloaded on 21 February 2021
Copyright The Animal Facts 2023