In an incident that provided a tragic reminder of why great apes don't belong behind bars in captivity, an orangutan at the Dortmund Zoo in Germany bit off the arm of a baby orangutan who reached into his enclosure from an adjoining one.
The orangutan, a large male named Walter, made headlines recently for "predicting" the winner of a football match -- a PR stunt set up by the zoo every year. He had been separated from the orangutan baby, named Yenko, and the baby's adoptive mother, an ape named Toba. It was believed that Walter was jealous of the attention the baby was receiving from Toba. When Yenko reached his hand into Walter's cage, the adult orangutan pounced, biting off his arm. The zoo should have been more cognizant of the danger Yenko was in, and protected the baby from potential harm.
Luckily, Yenko was saved by zoo staff, who conducted an emergency operation but were unable to reattach the severed limb. The episode serves as a dire warning against keeping orangutans in cages, especially keeping in mind their intelligence and emotional capacities.