Speaking of which, to get back to the topic, do monkeys/apes kill each other besides survival? In other words, they may do it for fun or pleasure.
Support your statement that monkeys/apes may kill each other for fun.
I asked a question. Can you answer it?
You made an utterly indefensible statement which you obviously cannot support.
Why chimpanzees attack and kill each other
Bands of chimpanzees violently kill individuals from neighboring groups in order to expand their own territory, according to a 10-year study of a chimp community in Uganda that provides the first definitive evidence for this long-suspected function of this behavior.
Read more at: Why chimpanzees attack and kill each other
For myself, I'll cite Jane Goodall's study of chimpanzees as the natural analogy to human tribal customs that evolves into law (and which codes morality). Furthermore, we consistently see humans -- with no specific religious connotation, have survival-based laws that preclude wanton murder and thievery. Further still, we see simple indigenous tribes have better morality than industrial nations have -- for instance, many tribes have no concept of thievery because they communally share everything.
You made a statement that you refuse to support. Can you support it?
Again, I asked a question to get back on topic. I don't think it's just territorial, but to attract better mates. Both exhibit behaviors to attract better mates.
Monkey Reproduction - Monkey Facts and Information
Here's two troubling, puzzling videos though which triggered my question. They are attacking their own as food and also killing a defenseless baby. Graphic, so you may not want to watch. Your link discusses it and tries to tie it to human warfare which has nothing to do with it. The so-called apes to humans theory is suppose to be the other way. They can be trained to be social and domesticated, but the wild monkeys are dangerous to humans.
So, there is no indication that monkeys kill for fun.
Why would you suggest they do and then retreat from providing support fir your suggestion?
Otherwise, the “apes to humans” nonsense is a narrative coming from those ignorant of science and/or the crackpots associated with the ID’iot creationist cults.