Editing European bison (section)

===Reproduction===
The rutting season occurs from August through to October. Bulls aged 4–6 years, though sexually mature, are prevented from mating by older bulls. Cows usually have a gestation period of 264 days, and typically give birth to one calf at a time.<ref name="pucek" />

On average, male calves weigh {{convert|27.6|kg|lb|sigfig=3|abbr=on}} at birth, and females {{convert|24.4|kg|lb|sigfig=3|abbr=on}}. Body size in males increases proportionately to the age of 6 years. While females have a higher increase in body mass in their first year, their growth rate is comparatively slower than that of males by the age of 3–5. Bulls reach sexual maturity at the age of two, while cows do so in their third year.<ref name="pucek" />

European bison have lived as long as 30 years in captivity,<ref name="babalu">{{cite news |first=Luísa |last=Medeiros |url=http://www.correiobraziliense.com.br/app/noticia182/2009/09/03/cidades,i=139677/EXEMPLAR+DE+BISAO+FEMEA+QUE+VIVE+NO+ZOOLOGICO+DE+BRASILIA+PODE+SER+O+MAIS+VELHO+DA+ESPECIE.shtml |title=Female European bison in Brasília Zoo may be the species oldest |date=3 September 2009 |work=correiobraziliense.com.br |access-date=3 September 2009 |archive-url=https://web.archive.org/web/20090904232217/http://www.correiobraziliense.com.br/app/noticia182/2009/09/03/cidades,i=139677/EXEMPLAR+DE+BISAO+FEMEA+QUE+VIVE+NO+ZOOLOGICO+DE+BRASILIA+PODE+SER+O+MAIS+VELHO+DA+ESPECIE.shtml |archive-date=4 September 2009 |url-status=dead }}(in Portuguese)</ref> but in the wild their lifespan is usually between 18 and 24 years, with females living longer than males.<ref name=żubryonline>{{cite web|title = ŻubryOnline|url = http://www.lasy.gov.pl/pl/informacje/kampanie_i_akcje/zubryonline|publisher = Lasy Państwowe|date = 4 November 2019|access-date = 30 November 2019|archive-date = 8 December 2019|archive-url = https://web.archive.org/web/20191208130016/http://www.lasy.gov.pl/pl/informacje/kampanie_i_akcje/zubryonline|url-status = live}}</ref> Productive breeding years are between four and 20 years of age in females, and only between six and 12 years of age in males.