Argentine tegus typically brumate for a large portion of the year while columbians stay active. My argentines have always started going inactive around August and I usually don't see them at all from October-February, then become more active around March-April. Argentines get larger and are more easy to calm down - could have something to do with them being captive bred on a larger scale but even in the wild argentines aren't really timid about approaching humans; especially true where food is involved. As far as I know, no columbian/gold tegus are captive bred in the states and all are WC/farmed imports. Argentine tegus have beaded scales while columbians are smooth. Argentine tegus will take a larger range of food items from meat to fruits, columbians are almost entirely carnivorous but may take a bit of fruit occasionally.