Is this world's saddest animal?

• Arturo is said to be depressed since his friend Pelusa died two yrs ago
• 29-yr-old's lonely life is causing him to display 'abnormal behaviour'

Arturo, a polar bear living in South America is called the ‘world’s saddest animal’. He sits in a concrete enclosure at Mendoza Zoo in Argentina in temperatures of up to 40C (104F) and is said to have been depressed since his long-term friend Pelusa died two years ago.

It is claimed the 29-year-old’s lonely life is causing him to display abnormal behaviour, including tilting his head and showing his teeth while pacing back and forth and rocking from side to side.

Arturo - Spanish for Arthur - has been at the zoo for two decades, and has had no contact with his own kind since Pelusa died. Now, campaigners are worried that he is suffering mental health issues. US singer Cher, 68, said on Twitter: ‘Don’t cry for him, Argentina? No tears of Mrs Cristina Fernandez de Kirchner for tortured polar bear Arturo. Your hands are stained with his blood when he dies.’ Animal rights activists now want Arturo - whose only access to cooling water in his enclosure is said to be a pool just 20in (50cm) deep - moved to another zoo that offers cooler conditions.

Mendoza Zoo blocked an effort five months ago to move Assiniboine Park Zoo in Winnipeg, Canada - where a new International Polar Bear Conservation Centre is located, reported the Sunday People.

The zoo did not believe the bear would survive the two-day trip, with director Gustavo Pronotto saying the medical board had made a decision - and officials were keen to ‘avoid a big mistake’.

He added at the time that the bear was in ‘good condition’, explaining that the life expectancy of one of the animals is just over 20 years - but in captivity, they can often live to see the age of 30.

Pronotto said: “We must avoid a big mistake, like his death during the trip or upon arrival. One must evaluate the risks carefully. He is old, and this would require many hours of anaesthesia.”

Greenpeace had gathered 160,000 signatures in a campaign to transfer Arturo urgently to Canada, which it said has weather that more closely resembles what occurs in his natural habitat.

Argentinian professor Fernanda Arentsen, who teaches at Université de Saint-Boniface in Winnipeg, has written to her government and the Canadian Embassy in Buenos Aires over the issue. She told the Winnipeg Free Press last year: ‘You can see he is going crazy. He moves the way polar bears do when they are suffering a lot of stress.

He has been filmed rocking back and forth in a way that signals distress. It breaks my heart to see it. I’m from Mendoza. I know how hot summer is. There is no way for him to escape the heat.