Hi Vic. I believe that hormone levels may well vary in different tortoise species. This seemed to be the case when one vet I know developed a blood test for sexing tortoises about 15 years ago which he said worked at 100% accuracy in Desert and Spurred Tortoises. He determined this after the blood test sexing by euthanizing and dissecting the animals in order to determine if the blood test was correct!!! The same test failed to be correct just about half the time when we tried it on adult Radiated Tortoises whose sexes were already known.

AS for the other question, I think it is definitely possible for male tortoises to become sterile, both from overheating and from infections.

Bill