U.S. & World

BERLIN (AP) ― Knut the superstar polar bear turns 2 on Friday looking nothing like the button-eyed ball of white fluff who captured hearts around the world.

The star of the Berlin Zoo is a fully grown bear with yellowish fur who, at 440 pounds, has grown too big for his enclosure. Worried fans are lobbying for him to stay, but zoo officials say he will have to move if they do not build a new enclosure, which appears virtually impossible due to lack of space.

Knut lives in a small section of the current enclosure, home to Knut's parents, Tosca and Lars, and two older females. Bearkeeper Heiner Kloes said Knut, who will reach sexual maturity around the age of 2, urgently needs enough space for both him and a fertile mate.

The zoo's two eligible female bears will be too old to have cubs by the time Knut is ready to reproduce. Scientists estimate that there are between 20,000 and 25,000 polar bears in the wild, according to the International Union for Conservation of Nature, and the species is listed as a threatened species under the U.S. Endangered Species Act. Canada and Russia have listed polar bears as a species of concern, citing shrinking habitats.

"The survival of the species is more important than any individual," Kloes said. "I won't hang on to Knut if it means keeping him with an old lady," Kloes said, noting the zoo is already filled with enclosures for other animals.

With Knut likely on the way out, the zoo is keeping his birthday low-key. It is planning a cake made of fruit rather than a big party like the one it threw last year for the Vanity Fair "cover bear," who shared the front of one issue with Leonardo DiCaprio.

The zoo has credited Knut with a 27 percent increase in visitors in 2007 and profits of nearly euro6.8 million ($8.6 million) from products with Knut's image, including stuffed animals, T-shirts, mugs and DVDs.

Knut has also had to contend with competition. Nuremberg city and zoo officials introduced their own cub, Flocke, in April with the fanfare of a movie premiere or record release.

A week later, Stuttgart's Wilhelma zoo presented Wilbaer, another adorable white ball of fluff.

But that has barely affected Knut's status as the Berlin Zoo's main attraction.

Doris Webb, 65, has followed Knut since he was first presented to the world by the keeper who raised him by hand after he was rejected by his mother. Since April, Webb has gathered more than 21,000 signatures in support of keeping Knut in Berlin.

"We want to show how important it is for Berlin, for the people here -- and for Knut himself," she said.

The zoo in the city of Neumuenster owns Lars the bear and has the right to his son Knut. That zoo's manager, Peter Druewa, told The Associated Press that if Berlin can't accomodate Knut's needs, he will have to find a place that can.

"If Berlin doesn't want to build a new enclosure -- or expand one of the existing ones -- we'll need to find a new place for him," Druewa said.

But there is no shortage of potential suitors who would be happy to offer a suitably roomy new home for Knut and a future mate.

Web site Unibet is placing odds on the zoo likeliest to get the bear, with Zoom Erlebniswelt in Germany the top contender, followed by Tierpark Neumuenster in Germany and Sweden's Orsa Bjornpark. Also tipped, at longer odds, are zoos in Norway, Finland, Denmark, Estonia and Spain.

Torbjorn Wallin, chief executive of Orsa Gronklitt AB, which runs the Orsa bear park 200 miles (320 kilometers) northwest of Stockholm, said his company has been in talks with Berlin Zoo about Knut's future for 18 months.

Wallin declined to discuss details but said a suitable mate, rather than money, had been the focus of discussions.

Wallin said other zoos and parks had shown interest too.

"Of course there are others -- it's the world's most famous animal," he said. "It's as if Madonna would move to Stockholm."

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