I know the biome requirements, but this is not what I'm asking here. A little background, in my current game. I'm in a tropical swamp with high rainfall with the swamp part bieng hot and the mountain part bieng scorching, I believe. I had some saltwater crocs from the elves which I later began breeding and a lone alligator. I don't remember how I came to be looking at the wounds, but I noticed that one of my first gen crocs had light grey wounds to the heart, spine, brain, and a few others for some reason (none of them have been in combat). I wondered about the others and so I checked. Their children had light grey wounds on just about everything, including the hatchlings. The alligator had similar wounds as the earlier ones mentioned. I checked my other critters, Grizzly Bear: fine (although you'd think it would suffer in this particular climate), Tiger: fine, Cougars: fine, Leopards: fine, Jaguar: fine, Hippos: fine, Elephants: fine, and Cheetah: fine. All of the mammals and even my dwarves didn't have a problem with the heat.
Since I didn't know whether the reptiles health would degrade further or not, I had them all butchered.
So, anybody know why the reptiles weren't faring to well here? The ones the elves brought I could understand, but not the native born ones. I looked at the raws and the reptiles had no layering (for obvious reasons) and no homeotherm tag, so that might explain why. I had seen some Saltwater Crocs and Alligators roaming around in the early days of my fort, so I know this is the correct habitat. Maybe they needed some water to cool off in?
I'm wondering if it was a mistake to slaughter them all since they breed quickly enough tomake up for the wounds which would make them not optimal for war training or guards.