The 180 kilo gorilla Bokito, who jumped over a 3.5 metre ditch on Friday and attacked a woman at Rotterdam's Blijdorp zoo, had probably been provoked into making his escape, zoo officials said at the weekend.
The preliminary investigation showed that shortly before the attack, children had been throwing stones at the gorilla, officials said. In addition, the behaviour of his victim may have contributed.
Fifty-seven year old Petronella Yvonne de Horde was a frequent visitor to the gorilla enclosure and according to her daughter believed she had a 'special relationship' with Bokito. One keeper said the gorilla may not have found De Horde submissive enough when she sought eye contact with him.
'I know Bokito targeted my wife. We were looking at him and as we walked away we heard a splash and there he was behind us,' the victim's husband Gerrit de Horde told the Volkskrant.
The gorilla grabbed the woman and dragged her several metres before making for the restaurant where he was eventually recaptured.
Bokito's keeper Fred Rueb told the paper the gorilla's behaviour had changed in recent weeks, since another gorilla group with a dominant male had been moved to Shanghai.
Bokito, who was raised by hand in Germany, was sent to Blijdorp in 2005 because he was too used to humans and did not show the 'desired group behaviour', the Volkskrant said.
His victim underwent a second round of operations on Sunday. She has a broken wrist and lower arm, a crushed hand and dozens of bites. Husband De Horde said surgeons told him his wife's hand may never recover.
'There will be a hefty damages claim,' he told the Volkskrant. 'They knew he was an escape-risk. He'd done it before.' Nevertheless, he said his wife did not bear Bokito, 11, any malice.