'Forgiving' is not a trait ascribed to animals. Neglected/abused animals can learn to trust if treated properly.
Psst... you and I are animals too... therefore, technically forgiveness is ascribed to animals quite a lot
I recall reading some research on baboons or macaques, as well as kangaroos, I think?... on them forgiving one another after squabbling...
... “forgiveness” in those studies being quantified by behaviors, such as grooming, sharing food, etc.
@Sobek ”forgiveness” is likely the wrong word... as sourland mentioned chickens do seem to learn and relearn to trust though.
In any case to get a real answer to this question, you’d likely have to qualify the world “forgiveness” as a set of behaviors observed in chickens, and understand a bit about how chickens remember things, which is different than the way people and other animals do.
But I’m sure there are a lot of anecdotal stories of chickens learning to trust again, that folks would call “forgiveness”.
It’s an interesting question though, particularly because forgiveness is one of those things that human animals as a whole kinda suck at, lol