Do animals have the concept of death and mortality?

What about the different abilities of individual animals within a group? Are we limiting the possibilities by assuming certain things? 

Good post (not read the linked page yet).

I wasn't intending to limit anything. In one sentence I used "sometimes/often/rarely" and that applies to much of what I write. I have ideas, but not certainties. And sometimes my ideas are just playful rather than realistic, but I think it's necessary to do so, allow a bit of leeway for just playing with ideas.