Editing Brown bear (section)

===Reproduction===
[[File:Ähtärin karhut 24.jpg|thumb|Pair of mating brown bears at the [[Ähtäri Zoo]] in [[Ähtäri]], Finland]]

The [[mating season]] occurs from mid-May to early July, shifting to later in the year the farther north the bears are found.<ref>{{cite journal|author1=Herrero, S. |author2=Hamer, D. |year=1977|title=Courtship and copulation of a pair of grizzly bears, with comments on reproductive plasticity and strategy|jstor=1379352|doi=10.2307/1379352|journal=Journal of Mammalogy|volume= 58|issue=#3|pages=441–444}}</ref> Brown bears are [[polygynandry|polygynandrous]], remaining with the same mate for a couple of days to a couple of weeks and mating multiply during the mating season. Outside of this narrow time frame, adult male and female brown bears show no sexual interest in each other.<ref name="pasitschniak-arts1993mamsp"></ref><ref name= Steyaert>{{cite journal|author1=Steyaert, S. M. |author2=Endrestol, A. |author3=Hacklaender, K. |author4=Swenson, J. E. |author5=Zedrosser, A. |year=2012|title=The mating system of the brown bear ''Ursus arctos''|doi=10.1111/j.1365-2907.2011.00184.x|journal= Mammal Review|volume= 42|issue=#1|pages=12–34|bibcode=2012MamRv..42...12S }}</ref> Females mature sexually between the ages of four and eight.<ref name= Craighead/> Males first mate about a year later, when they are large and strong enough to compete with other males for mating rights.<ref name= White>{{cite journal|author1=White, D. J. |author2=Berardinelli, J. G. |author3=Aune, K. E. |year=1998|title=Reproductive characteristics of the male grizzly bear in the continental United States|jstor=3873161|journal=Ursus |volume=10|pages=497–501}}</ref> Males will try to mate with as many females as they can; usually a successful male will mate with two females in a span of one to three weeks.<ref name="Walker"/><ref name= White/> Similarly, adult female brown bears can mate with up to four, sometimes even eight, males while in oestrus (heat), potentially mating with two in a single day.<ref name= Ambarl>{{cite journal|author=Ambarlı, H. |title=Litter size and basic diet of brown bears (''Ursus arctos'', Carnivora) in northeastern Turkey|journal=Mammalia|volume=80|issue=2|doi=10.1515/mammalia-2014-0111|year=2016|s2cid=87968464}}</ref> Females come into [[oestrus]] every three to four years, with an outside range of 2.4 to 5.7 years. The [[urine marking]]s of a female in oestrus can attract several males via scent.<ref>{{cite journal|author1=Halloran, D. W. |author2=Pearson, A. M. |year=1972|title=Blood chemistry of the brown bear (''Ursus arctos'') from southwestern Yukon Territory, Canada|doi=10.1139/z72-112|pmid=5038730|journal=Canadian Journal of Zoology|volume= 50|issue=#6|pages=827–833|bibcode=1972CaJZ...50..827H }}</ref> Dominant males may try to sequester a female for her entire oestrus period of approximately two weeks, but usually are unable to retain her for the entire time.<ref name= Feldhamer/><ref name= Bellemain/> [[copulation (zoology)|Copulation]] is prolonged and lasts for over 20 minutes.<ref name= Feldhamer/><ref>{{cite journal|author1=Craighead, J. J. |author2=Hornocker, M. G. |author3=Craighead, F. C. Jr |year=1969|title=Reproductive biology of young female grizzly bears|journal= J. Reprod. Fertil. |volume=Suppl. 6|pages= 447–475}}</ref>

[[File:Grizzly Bear- Sow and cubs (5728173840).jpg|thumb|left|Grizzly bear cubs often imitate their mothers closely.|alt=A mother bear standing next to her cubs]]

Males take no part in raising cubs – parenting is left entirely to the females.<ref name= Dahle/><ref>{{Cite book |last=Corbet |first=Gordon Barclay |url=https://books.google.com/books?id=GD4_AAAAYAAJ |title=The Terrestrial Mammals of Western Europe |date=1966 |publisher=Foulis |location=London, UK |pages=52–55 |language=en}}</ref> Through the process of [[delayed implantation]], a female's fertilized egg divides and floats freely in the uterus for six months. During winter dormancy, the fetus attaches to the [[uterus|uterine]] wall. The cubs are born eight weeks later, while the mother sleeps. If the mother does not gain enough weight to survive through the winter while gestating, the embryo does not implant and is reabsorbed into the body.<ref name="Craighead">Craighead, J. J., Sumner, J. S., & Mitchell, J. A. (1995). "The grizzly bears of Yellowstone: their ecology in the Yellowstone ecosystem, 1959–1992". Island Press. pp. 21–56</ref><ref>{{cite journal |name-list-style=amp |author1=Tsubota, T. |author2=Kanagawa, H. |s2cid=84359252 |year=1993|title=Morphological Characteristics of the Ovary, Uterus and Embryo during the Delayed Implantation Period in the Hokkaido Brown Bear (''Ursus arctos yesoensis'')|journal=Journal of Reproduction and Development|volume= 39|issue=#4|pages=325–331|doi=10.1262/jrd.39.325|doi-access=free}}</ref><ref>{{cite journal |name-list-style=amp |author1=Hensel, R. J. |author2=Troyer, W. A. |author3=Erickson, A. W. |year=1969|title=Reproduction in the female brown bear|jstor=3799836|journal=The Journal of Wildlife Management|pages= 357–365|volume=33|issue=#2 |doi=10.2307/3799836}}</ref> Litters consist of as many as six cubs, though litters of one to three are more typical.<ref>{{cite journal|url=http://www.bearbiology.com/fileadmin/tpl/Downloads/IBN_Newsletters/IBN_May_2005.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.bearbiology.com/fileadmin/tpl/Downloads/IBN_Newsletters/IBN_May_2005.pdf |archive-date=2022-10-09 |url-status=live |author1=Pazetnov, V. A. |author2=Pazetnov, S. V. |name-list-style=amp |year=2005|title=Female brown bear with six cubs|journal= International Bear News |volume=14|issue=#2|page=17}}</ref> The size of a litter depends on factors such as geographic location and food supply.<ref name= Steyaert></ref> At birth, cubs are blind, toothless and hairless and may weigh {{convert|350|to|510|g|lb|abbr=on}}. There are records of females sometimes adopting stray cubs or even trading or kidnapping cubs when they emerge from hibernation (a larger female may claim cubs from a smaller one).<ref name="Hunter"/><ref>{{cite journal|author1=Erickson, A. W. |author2=Miller, L. H. |year=1963|title=Cub adoption in the brown bear|journal=Journal of Mammalogy|volume= 44 |issue=#4 |pages=584–585 |doi=10.2307/1377153 |jstor=1377153}}</ref><ref>{{cite journal|url=https://pubs.er.usgs.gov/publication/1012856|author1=Barnes, V. Jr|author2=Smith, R.|year=1993|title=Cub adoption by brown bears (''Ursus arctos middendorffi'') on Kodiak Island, Alaska|journal=Canadian Field-Naturalist|volume=107|issue=3 |pages=365–367|doi=10.5962/p.357155 |access-date=12 December 2016|archive-date=20 December 2016|archive-url=https://web.archive.org/web/20161220042307/https://pubs.er.usgs.gov/publication/1012856|url-status=live|doi-access=free}}</ref> Older and larger females within a population tend to give birth to larger litters.<ref>{{cite journal|author=Stringham, S. F. |year=1990|title=Grizzly bear reproductive rate relative to body size|journal=Bears: Their Biology and Management|volume=8|pages= 433–443|doi=10.2307/3872948|url=https://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_8/Stringham_Grizzly_8.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_8/Stringham_Grizzly_8.pdf |archive-date=2022-10-09 |url-status=live|jstor=3872948}}</ref> The cubs feed on their mother's milk until spring or early summer, depending on climate conditions. At this time, the cubs weigh {{convert|7|to|9|kg|lb|abbr=on}} and have developed enough to follow and forage for solid food with their mother over long distances.<ref name="pasitschniak-arts1993mamsp"></ref><ref>{{cite journal|author1=Dahle, B. |author2=Zedrosser, A. |author3=Swenson, J. E. |year=2006|title=Correlates with body size and mass in yearling brown bears (''Ursus arctos'')|doi=10.1111/j.1469-7998.2006.00127.x|journal=Journal of Zoology|volume= 269|issue=#3|pages=273–283}}</ref>

[[File:Kuusamo, Finland - Bears3.jpg|thumb|Brown bear cub in Finland]]

The cubs are dependent on the mother and a close bond is formed. During the dependency stage, the cubs learn (rather than inherit as instincts from birth) survival techniques, such as which foods have the highest nutritional value and where to obtain them; how to hunt, fish, and defend themselves; and where to den.<ref name= Novak/> Increased brain size in large carnivores has been positively linked to whether a given species is solitary, as is the brown bear, or raises offspring communally. Thus, the relatively large, well-developed brain of a female brown bear is presumably key in teaching behavior.<ref>{{cite journal|pmid=8202515|pmc=44022 |author=Gittleman, J. L. |year=1994|title=Female brain size and parental care in carnivores|journal=Proceedings of the National Academy of Sciences|volume=91|issue=#12|pages=5495–5497|bibcode=1994PNAS...91.5495G|doi=10.1073/pnas.91.12.5495|doi-access=free }}</ref> The cubs learn by following and imitating their mother's actions during the period they are with her.<ref name="Hunter" /> Cubs remain with their mother for an average of 2.5 years in North America, and gain independence from as early as 1.5 years of age to as late as 4.5 years.<ref name= Feldhamer/> The stage at which independence is attained may generally be earlier in some parts of [[Eurasia]], as the latest date which mother and cubs were together was 2.3 years. Most families separated in under two years in a study in [[Hokkaido]], and in Sweden most yearlings were their own.<ref name=mano>{{cite journal|author1=Mano, T. |author2=Tsubota, T. |year=2002|title=Reproductive characteristics of brown bears on the Oshima peninsula, Hokkaido, Japan|jstor=1383508|doi=10.1644/1545-1542(2002)083<1026:RCOBBO>2.0.CO;2|journal=Journal of Mammalogy|volume= 83|issue=#4|pages=1026–1034|doi-access=free}}</ref><ref>{{cite journal|author1=Dahle, B. |author2=Swenson, J. E. |year=2003|title=Family breakup in brown bears: are young forced to leave?|doi=10.1644/1545-1542(2003)084<0536:FBIBBA>2.0.CO;2|journal= Journal of Mammalogy|volume= 84|issue=#2|pages=536–540|doi-access=free}}</ref> Brown bears practice [[Infanticide (zoology)|infanticide]], as an adult male bear may kill the cubs of another.<ref name= Bellemain/> When an adult male brown bear kills a cub, it is usually because he is trying to bring the female into oestrus, as she will enter that state within two to four days after the death of her cubs.<ref name= Bellemain/> Cubs may flee up a tree when they see a strange male bear approaching. The mother often successfully defends them, even though the male may be twice as heavy as she. However, females have been known to die in such confrontations.<ref name= Bellemain/><ref>{{cite journal|author1=Swenson, J. E.|author2=Dahle, B.|author3=Sandegren, F.|year=2001|title=Intraspecific predation in Scandinavian brown bears older than cubs-of-the-year|journal=Ursus|pages=81–91|jstor=3873233|url=https://www.researchgate.net/publication/237374836|volume=12|access-date=12 December 2016|archive-date=16 November 2017|archive-url=https://web.archive.org/web/20171116185901/https://www.researchgate.net/publication/237374836_Intraspecific_predation_in_Scandinavian_brown_bears_older_than_cubs-of-year|url-status=live}}</ref><ref name="Mörner">{{cite journal|author1=Mörner, T. |author2=Eriksson, H. |author3=Bröjer, C. |author4=Nilsson, K. |author5=Uhlhorn, H. |author6=Ågren, E.  |author7=Segerstad, C. H. |author8=Jansson, D. S. |author9=Gavier-Widén, D. |year=2005|title=Diseases and mortality in free-ranging brown bear (''Ursus arctos''), gray wolf (''Canis lupus''), and wolverine (''Gulo gulo'') in Sweden|journal=Journal of Wildlife Diseases|volume= 41|issue=#2|pages=298–303|pmid=16107663|doi=10.7589/0090-3558-41.2.298|s2cid=43774546 |doi-access=free}}</ref>