Can some one tell me the average growth rate of the BCI RTB?
I don't think so. I think it depends on a few factors including genetics and the quantity the snake is fed. I've seen some BCIs that were several years old and only 3-4 feet long, and others that were over 6 feet in a couple of years.
Like most snakes, the more you feed them the faster they'll grow... Of course if you feed them too much too fast, you will risk a number of health issues such as liver problems or obesity.
Sounds fine. 3' is about the biggest I would let any boa get in the first year personally. I have a female in the 6'+ range thats about 4 years old and her growth is slower than ever. Just feed at a rate that they keep their body weight in check without getting to obese or skinny and you will have a healthy boa. Fat boas are just a heart problem waiting to happen
~Jake~
Too many boas to list and a few balls as well