BERLIN - After last month's death of the beloved polar bear Knut, the eyes of animal enthusiasts around the world turned to Berlin. The controversy that surrounded the bear in life was following him to death, as more than 70 German and foreign reporters crowded into one particular press conference in order to find out what killed him unexpectedly at the age of four.

The official conclusion was that Knut had drowned after he fell into the moat of his enclosed living space. The reason for his fall was a weak spell caused by encephalitis, an apparently protracted viral inflammation in his brain.

It was a sad end for the bear who garnered global media attention after he was born in captivity and was hand-reared after his mother rejected him, which set off criticisms from animal-rights activists. His death sparked even more debates.

Zoo director Bernhard Blaszkiewitz, along with a contingent of eight specialists from the Institute for Zoo and Wildlife Research (IZW), the Veterinary Institute of the Free University and the Natural History Museum, invited media representatives to the Friedrichsfelder Animal Park in order to inform the public about the circumstances surrounding Knut's death. IZW director Heribert Hofer noted that his team had been working "literally day and night" since March 19th to be able to release these "preliminary" autopsy results to the public.

Haste had seemed necessary from the zoo director's perspective, looking for quick results to satisfy the curiosity of Knut's many fans around the world, and in Berlin (the flocks of elderly ladies who made their way each day to visit the bear's enclosure, even after his death, were especially eager to know more). But they also wanted quick results to help clear Blaszkiewitz and the zoo employees of any lingering suspicions of any wrongdoing after March 19, the day on which a crowd of zoo visitors looked on in horror as Knut died before their eyes.

Autopsy reports now show that even if Knut had fallen on dry land, "he would have had no chance of survival," said IZW-pathologist Claudia Szentiks. "The (encephalitis) inflammation in his brain was deadly, and it must have already existed for weeks or months." The exact nature of the inflammation is unknown, as is the virus that caused it. Hofer does not rule out the possibility that they will discover an entirely new pathogen upon further investigation.

Some 21,000 images were taken of Knut's brain. Using this data set, experts were able to make a scale model of his skull and immediately rule out two causes of death: skull deformities and genetic brain defects that lead to an epileptic seizure, which is what had been widely speculated.

Inbreeding was not the cause of death

Excluding genetic damage as a cause of death also rules out the possibility that Knut died as a result of inbreeding, an accusation that had recently been leveled at zoo directors. Immediately after the bear's death, some animal rights activists launched a campaign to ban the breeding of polar bears in the zoo. Zoo director Blaszkiewitz pointed out that Knut's parents had not been related in any way, and that any relationships within his paternal line had not harmed him.

Another accusation against the zoo was that Knut's accommodation with three female polar bears might have put him under constant stress, and that a resulting fainting spell could have made him fall into the water. However, the autopsy team revealed that there was "no stress, no trauma."

"We have thoroughly analyzed all of his individual organs," said Szentiks, adding that the bear's immune system did not appear to be weakened in any way.

The deeper allegation in this case was that Knut -- who had been abandoned by his mother -- was hand raised by bottle by his human keeper Thomas Dörflein, and the use of the wrong milk could have permanently damaged his immune system. But even this scenario has now been dismissed by the experts.

During his lifetime, Knut was the most famous bear in the world. In death, he has set another record by what may be the most complex wildlife autopsy of all time. And the investigation isn't even over yet.

Read the original article in German.

Photo - Marmontel