Editing Reindeer (section)

=== Reproduction and life cycle ===
{{Further|Rut (mammalian reproduction)#Cervidae}}
Reindeer mate in late September to early November, and the gestation period is about 228–234 days.<ref name="Bergerud2014">{{citation |title=Caribou |first=A.T. |last=Bergerud |url=http://www.thecanadianencyclopedia.ca/en/article/caribou/ |publisher=The Canadian Encyclopedia |date=29 April 2014 |access-date=3 September 2014 |url-status=live |archive-url=https://web.archive.org/web/20141207050757/http://www.thecanadianencyclopedia.ca/en/article/caribou/ |archive-date=7 December 2014 }}</ref> During the mating season, bulls battle for access to cows. Two bulls will lock each other's antlers together and try to push each other away. The most dominant bulls can collect as many as 15–20 cows to mate with. A bull will stop eating during this time and lose much of his body fat reserves.<ref name="animalcorner.co.uk">{{cite web|url=http://www.animalcorner.co.uk/wildlife/caribou.html |title=Caribou at Animal Corner |url-status=dead |archive-url=https://web.archive.org/web/20121029063613/http://www.animalcorner.co.uk/wildlife/caribou.html |archive-date=29 October 2012 }}</ref>

To calve, "females travel to isolated, relatively predator-free areas such as islands in lakes, peatlands, lake-shores, or tundra."<ref name="SARA2014" /> As females select the habitat for the birth of their calves, they are warier than males.<ref name="Bergerud2014" /> Dugmore noted that, in their seasonal migrations, the herd follows a female for that reason.<ref name="Dugmore1913" /> Newborns weigh on average {{cvt|6|kg}}.<ref name="Naughton2011" /> In May or June, the calves are born.<ref name="Bergerud2014" /> After 45 days, the calves are able to graze and forage, but continue suckling until the following autumn when they become independent from their mothers.<ref name="animalcorner.co.uk"/>

Bulls live four years less than the cows, whose maximum longevity is about 17 years. Cows with a normal body size and who have had sufficient summer nutrition can begin breeding anytime between the ages of 1 and 3 years.<ref name="Bergerud2014" /> When a cow has undergone nutritional stress, it is possible for her to not reproduce for the year.<ref>{{Cite journal |title= Reproductive Pauses by Female Caribou |journal= Journal of Mammalogy |date= 18 February 1994 |issn= 0022-2372 |pages= 10–13 |volume= 75 |issue= 1 |doi= 10.2307/1382230 |first= Raymond D. |last= Cameron |jstor= 1382230 }}</ref> Dominant bulls, those with larger body size and antler racks, inseminate more than one cow a season.