If I were a long-lived species that had relatively low numbers of offspring with an extended maturation time spent in social groups...

... it seems pretty reasonable that a death could trigger a lifelong vendetta.

If humans were casually killed by other animals at the rate we casually kill even the most intelligent non-human species, we'd exterminate that other species. Oh wait, we have.

I have always wondered why the Southern Resident orcas in the Pacific Northwest aren't more skittish of humans. We captured them, killing many in the process, back in the 1970s. Many local bystanders and observers reported the orcas crying and screaming being completely disheartening and upsetting.

https://www.seattletimes.com/seattle-news/environment/the-or...

https://www.timescolonist.com/local-news/50-years-ago-seven-...

https://us.whales.org/our-4-goals/end-captivity/the-penn-cov...

One of them still lives and has been in a single, tiny tank in Florida for five decades, alone for three decades. Completely sickening.