Editing Bearded seal (section)

==Reproduction and lifecycle==
[[Image:Beardedsealpup.jpg|thumb|left|Bearded seal pup]]
Bearded seals give birth in the spring. In the [[Northern Canada|Canadian Arctic]], seal pupping occurs in May.<ref name="uoguelph"/> In Svalbard, bearded seals reach [[sexual maturity]] at 5 or 6 years of age.<ref>{{cite journal | last1 = Andersen | first1 = Magnus | display-authors = etal | year = 1999 | title = Growth, age at sexual maturity and condition in bearded seals (Erignathus barbatus) from Svalbard, Norway | url = https://brage.bibsys.no/xmlui/bitstream/handle/11250/174308/AndersenPolarBiol1999.pdf?sequence=1 | journal = Polar Biology | volume = 21 | issue = 3| pages = 179–185 | doi = 10.1007/s003000050350 | bibcode = 1999PoBio..21..179A | hdl = 11250/174308 | s2cid = 37623370 | hdl-access = free }}</ref> Further south, in [[Alaska]], most pups are born in late April.{{clarify|reason=See talk page|date=March 2013}} Pups are born on small drifting ice floes in shallow waters, usually weighing around {{convert|30|–|40|kg|abbr=on}}. They enter the water only hours after they are born, and quickly become proficient divers. Mothers care for the pups for 18–24 days, during which time the pups grow at an average rate of {{convert|3.3|kg|abbr=on}} per day. During this time, pups consume an average of {{convert|8|L|abbr=on}} of milk a day. By the time they are weaned, the pups have grown to about {{convert|100|kg|abbr=on}}.

Just before the pups are weaned, a new mating cycle takes place. Females ovulate at the end of their lactation period, but remain close to their pups, ready to defend them if necessary. During the mating season, male seals will "sing", emitting a long-drawn-out warbling note that ends in a sort of moan or sigh. This sound may attract females, or may be used by the males to proclaim their territory or their readiness for breeding. Males occupy the same areas from one year to the next.<ref>{{cite book | title = Encyclopedia of the Arctic | author = Nuttal | publisher = Routlelege | location = New York, NY | year = 2005|display-authors=etal}}</ref>

Like many Arctic mammals, bearded seals employ a reproductive strategy known as [[delayed implantation]]. This means that the [[blastocyst]] is not implanted for two months after fertilization, most often becoming implanted in July. Thus, the seal's total [[gestation]] period is around eleven months, though its active gestation period is nine months.<ref>{{cite book | author = Perry, Judith E. | title = Seals of the World | publisher = Comstock Publishing Associates | location = Ithaca, NY | year = 1983 | page = 103}}</ref>

Natural predators of the bearded seal include polar bears, who rely on these seals as a major food source.<ref name="Bearded seal">{{cite web|title=Erignathus barbatus – bearded seal|url=http://animaldiversity.ummz.umich.edu/accounts/Erignathus_barbatus/|publisher=Animal Diversity Web}}</ref> [[Killer whale]]s also prey on these seals, sometimes overturning ice floes to reach them. [[Walrus]]es also eat these seals, mainly pups, but such predation is rare.<ref>Folkens, Peter (2002). ''National Audubon Society Guide to Marine Mammals of the World.'' New York, pg. 117.</ref>

Bearded seals are believed to live up to 31 years.<ref>National Marine Mammal Laboratory [http://www.afsc.noaa.gov/nmml/education/pinnipeds/bearded.php#die Bearded Seals] Retrieved May 1, 2016</ref>