I've been playing around with differentiating animal people in my
Furry Fortress mod. Mine are designed to replace dwarves instead of integrate them, since that's how it works for now, but here's what I got:
Vulps (Foxes) - Trancing, alcohol dependent, average stats, bites and scratches are primary, punches and kicks are secondary, natural biting skill of 1, dog teeth
Lagomers (Rabbits) - alcohol dependent, grazers, very agile, very fast gait, rodent teeth, should have larger than average legs, but I haven't gotten around to that
Komodos (Varanids) - carnivores, natural ambusher skill, dwarf-like strength and toughness, tail slap attack (which I never got to work), claws instead of nails
Anatos (Ducks) - amphibious (which doesn't work), high endurance (bird lungs)
Equids (Horse/Centaur) - centauroid body, hooves, large body size, penalty to mining skill
Leokin (Lion) - carnivore, claws, large body size, large eye teeth, males are larger than females and less common, males are natural fighters, females are natural hunters, penalty to mining skill
Ratuls (Honey Badgers) - a joke race, prone to rage, bone carn, maxed out toughness and disease resistance, fart reflex breath attack (like skunks), all ethics and values set to zero because they don't care
One of the things on my to-do list is to change their personality dispositions. So far, I've only done this with Ratuls to make them not care harder, and with Leokin males to make sure they can reproduce. I've noticed that changing the ethics and values for civilizations can have interesting impacts on how they behave. Komodos don't care about craftsmanship, so they don't get made if you melt down a masterwork. Lagomers like nature, so they don't mind being outdoors.
My experience so far has been that the interactions in Dwarf Fortress are vague enough that you can reuse a lot of features for different races, Komodos, Leokin and Ratuls all share a lot of traits, and small changes can make a big difference, for example Vulps are surprising good at fighting allegedly because of their preference for biting, but this is true of their legendary swordsvulps too, and the carnivore races promote a very different lifestyle and fortress design. I made a list of
mod tokens I would have liked to have that might turn into some useful differentiation ideas.