One of the bigger features of Redemption was the animals
you could interact with. Whether you shot at birds while traveling between towns or gripped your gun with fear after hearing a cougar growl in the distance, animals are a beloved feature.
From the first Red Dead Redemption 2 trailer
we have seen:
Animals are much more interactive among themselves. The first trailer showed a fox hunting a squirrel and vultures tearing into a coyote carcass.
Also in the scene with the buffalo you can see younger ones among the group (bottom-right):