The Day Is Done by Lester del Rey

A solitary Neanderthal, last of his kind, lives on the fringe of a Cro-Magnon camp, surviving on scraps and memories. Once a proud hunter, he now wrestles with irrelevance and humiliation in a world reshaped by change he neither asked for nor understands. When he learns there may be others like him still alive, a flicker of hope drives him toward one last quest for connection. But food is scarce, cruelty is easy, and even kindness comes with a sting.