Theories for the abnormal behaviour abound. Overfishing, some suggested, had forced the sharks closer to shore in search of other prey.

对这种反常行为有很多理论解释。有人推测说捕捞过度会迫使鲨鱼抵近海岸搜寻其他的食物。

youdao

Did anyone notice his abnormal behaviour?

有没有人注意到他反常的行为？

youdao

Researchers from Bristol University studied 77 animals in 13 zoos and found that almost half of the elephants displayed abnormal behaviour.

BBC: Elephants 'die earlier in zoos'

The abnormal behaviour declined and the chimps began to play together.

BBC: Lab chimps successfully treated with anti-depressants

But Dr Kranendonk found that the abnormal behaviour actually increased.

BBC: Lab chimps successfully treated with anti-depressants