"... We have a policy to preferentially harvest males over females, and the argument behind that is that the females are the ones doing the reproduction,"

Polar bears typically mate from the beginning of April to the end of May, when males follow the trails of females in heat.

If they like each other, they will mate over a period of about 2 1/2 weeks, after which the female is generally pregnant.

The male will then wander off in search of other females.

Study looked at the number of males that searched for and found females, how long the pairs stayed together, if the males found other mates, and how many females a male could fertilize in a breeding season.

Molnar said there currently appears to be no problem with the pregnancy rate. In Lancaster Sound, for example, 99 per cent of females find partners.

The paper says that if the number of males declined to a threshold of two males for every three females, it could lead to a dramatic and rapid reproductive collapse o