Idk if I haven't played the game enough but I'd like to see a lot more variation in groups.
Especially for carnivores, who are often alone except for the wolves and lions
Even the herbivores, I'd like to see lone individuals or small bachelor groups
#smaller groups/solitary animals
cold pumice
flat blade
I mean, it sorta of mimicks the social behaviour of animals IRL, foxes live in mated pairs, bear are often solitary and will only congregate in numbers around predictable food sources such as chokepoints during a salmon run.
ancient sand
Single animals were already added to the game in an update many months ago. All deer species can have solos, as can bears, wolves and lions. Aside from their herd size, they function exactly like any other herd (preset territory and zones, influenced by mean habitat fitness).
cold pumice
Probably I haven't played enough