Sunday, June 5, 2011

Icy Romance

What we first believed was a polar bear mother and cub, we are now convinced is actually a mating couple. The bears have been almost stationary for the last 4 days on the ice on Young Sund a few kilometers from Zackenberg Research Station. According to the literature, male polar bear will lead receptive females to areas with few seals to avoid competition from other males. Size does matter in aggressive encounters and males are about double the size of females. Only one presumed copulation have been observed with these guys. We have no idea how often they normally copulate but the ovulation has to be provoked by repeated copulations. The blastocyst is not implanted until late autumn. At that time the female will dig out a maternity den in huge snow drifts. The gestation is about 60 days after which one or two tiny young are born weighing only about 600g. When the female and young emerge from the den next spring, the weight of the young has increased to about 5-20kg. The female on the other hand can loose half of her weight. It has been a pleasure to watch "our bears" through binoculars and telescopes in safe distance, but it is also good a reminder to be alert and carry repellants and defense devices at all times in the field.