Polar bears
A file photo of twin polar bear cubs Gregor and Aleut are pictured with their mother Vera in their enclosure at the zoo in NurembergReuters

More than 5,000 polar bears in the Arctic are expected to give birth to cubs as the world is gearing up to ring in the New Year.

The World Wildlife Fund for Nature, which marks the polar bear birthday on 29 December, hopes the carnivorous species, classified as vulnerable, will multiply.

Since 2008 the birthday of polar bears has been celebrated on that day as scores of cubs are born during this period.

"Unfortunately, little is known about how many polar bears are in Russia, because a comprehensive study of only one [of the three] major group requires ... millions of dollars," Viktor Nikiforov, representing the Russian arm of the organisation, told RIA Novosti.

The Polar bears' numbers have been dwindling in recent years, but with large-scale international efforts, things are looking up. The bears, which have a life span of about 25 years, are often threatened by poachers, global warming and pollution.

Although exact numbers are not available, it is estimated that the global population of polar bears is anywhere between 20,000 and 25,000.

In the Russian Arctic alone, it is believed there could be around 6,000 polar bears.