I have to female tortoise, same age from the same batch and 1 is much bigger then the other, was told they are both females when i brought them, both are healthy & eating well, was the same size when i brought them.
A) are you sure they're both females? How oLd are they? It's tricky to sex under 4 years.
B) some tortoises grow a different rates, they are individuals after all! But have you noticed that the larger one is eating more than the other? A slow growing tortoise is a healthier tortoise!
