Some reports I have on animals of yours, in case other players interested in adopting the same ones are curious about them (in alphabetical order):
There were no crashes, strange glitches, or bugs found with the following:
Balkan Donkey - excellent breeders but on the slow side, make sure they are placed in an exhibit with ample space, especially when placed with other species. expect lots of fecal matter - I'd suggest installing a hack that lets you delete it yourself because your zoo staff will fall behind and not get to it fast enough and it'll affect their suitability. This isn't a critique of the animal, just something to keep in mind. Will eat a lot and deplete their food supply in the blink of an eye, make sure your zookeepers are around to replenish it. At the time of writing this I have 15.
Barbary Lion - builds prides slowly (screenshots coming in other threads soon), I'd say about average birth rate. Make the exhibits big enough that they won't complain about space but you don't have to go crazy. At the time of writing this I have 11.
Exmoor Pony - same as BD, keep an eye on them. their 'herds' are rather small. the same thing applies about feeding. At the time of writing this I have 7.
Highland Cattle - same as BD. the same thing applies about feeding. At the time of writing this I have 13.
North Country Mule Sheep - exceptionally good breeders, to the point that I had to start selling the babies after running out of space. Expect to see birthing messages about them every couple minutes. This makes sense for their species but just be mindful about it, don't make tiny exhibits for them especially if you're going to mix them with other species. the same thing applies about eating. At the time of writing this I have 39.
Regaliceratops - they appear to be solitary so if you adopt one or two of them it's likely they'll stay that way. They haven't produced offspring for me yet. At the time of writing this I have 3.
Snow Geese - again, don't make tiny exhibits for these guys. They like to make large flocks but you won't get birthing messages every two minutes. At the time of writing this I have 19.
Steppe Bison - they build their herds slowly but consistently, expect a lot of fecal matter and them depleting their food supply. build medium-to-large exhibits for them, especially when mixing with other species. At the time of writing this I have 10.
Tarpan - about the same characteristics as the steppe bison. At the time of writing this I have 9.