A male chimpanzee in a Swedish zoo planned hundreds of stone-throwing attacks on zoo visitors, according to researchers. Keepers at Furuvik Zoo discovered that the chimp collected and stored stones that he would later launch toward onlookers. (No one was injured.) Also, the chimp learned to recognize how and when parts of his concrete enclosure could be pulled apart to make further projectiles.
The findings were reported in the journal Current Biology. There has been scant evidence in previous research that animals can plan ahead. Crucial to the study is the fact that Santino, a chimpanzee at the zoo in the city north of Stockholm, collected the stones in a calm state, before the zoo opened in the morning. He threw the stones hours later in an "agitated" state – displaying his dominance to zoo visitors.
This suggests that Santino was anticipating a future mental state – an ability that has been difficult to definitively prove in animals, according to Mathias Osvath, a cognitive scientist from Lund University in Sweden and author of the new research. Read more at BBC News.