Berliners may be particularly fond of their zoo — Kloes says there are people who visit every day and know the animals better than he does — but it is Bao Bao and his disappointing love life that grips their imagination more than any other denizen.
He arrived from China when he was two years old, not long after Beijing first began handing out the cuddly looking bears in a bid to improve foreign relations.
London, Moscow, Vienna, Washington, Madrid and Paris have all benefited.
In 1980, it was Berlin's turn and Bao Bao arrived with his first companion, Tjen Tjen.
The pair was accompanied by former Chinese prime minister Hua Guofeng, who personally presented them to the German chancellor at the time, Helmut Schmidt.
The press and the public could not get enough of the bears when they first settled in at the Zoological Garden, which lies in the west of what was then still a divided city.
Tragedy struck not long afterwards when Tjen Tjen died of a virus just as she reached the age where she could have cubs.
Since then, the zoo has repeatedly tried and failed to find a mate that could give Bao Bao offspring and help save the endangered species, which turns sex shy in captivity.
"We have contacted the Chinese authorities with a view to hiring a female panda, but without success," Kloes says.
