So the chimps escaped hours earlier because they overheard the birthday cake plans?
Follow this: The chimps escape. They are doing whatever chimps do when they escape.
The couple arrives.
The chimps see them and remember them. They attack.
I've seen dogs do this. What problem do you have with this?
Animals don't have human intelligence but they do have social structure and they simply look at humans as other of what they are. That's why they're dangerous.
Chimps are smarter than greman sheperds and I've seen german sheperds to things that require as much recognition as this attack did. I've seen a dog launch an attack that required MORE functioning brain circurits than this particular attack did.
I read an article from a Fresno CA paper that gave some detail about the sequence of events. It appears that as the park owner was chasing the chimps, in an attempt to coral them back into their cage, she saw them attack the couple.
We’ve heard jealousy, sex drive, and inherent savage tendencies as explanations for the behavior. I wonder how much being chased had to do with it???
Chimps have the capacity and sometimes motives to hurt and/or kill other animals. Sometimes the motives are clear, and sometimes they aren’t. Sometimes a chimp might be sweet and kind. At other times it might be a vicious killer. Depends on the situation. Sound like another primate we know?