Most of every species gets pretty insane over mates. Evolution is about spreading your genes, not about prolonging your life. Obviously the latter is often useful to achieve the former, but not always. There are even numerous examples, such as black widows and bees, where death is even a part of procreation.

And I think the exceptions are often found to not really be exceptions. For instance chimps were once seen and framed, most famously by Jane Goodall, as peaceful animals who only engaged in violence when pushed to the extreme by some outside force. And in looking up info about bonobos I'm somewhat unsurprised to find that recent observations [1] are rather contrary to their reputation as the same sort of peaceful kumbaya type.

[1] - https://www.science.org/content/article/bonobos-hippie-chimp...