The extinction of humanity

Have you ever questioned whether there's a difference between the killing of one rhino and that of the chicken you just ate?

Both are individuals with their own lives like you or me and they have each gone extinct as a single being. It doesn't matter to you whether the species survives if you're the individual animal, right?

We talk about stopping a species from going extinct but because there are plenty of chickens it somehow becomes ok to kill individuals (so long as you only kill a proportion of them). 

Isn't it interesting the way people's minds work? They seem to see a species of animal as an entire entity and they fear the disappearance of that entity. But for the individual animal all it really has at the end of the day is it's own life.

Interestingly, since humans are animals do the same standards not apply to us? There are plenty of us on the planet so does it matter if a number of people are killed (so long as it's only a small proportion)?