Question: what is the difference between f1 and f5 savannah cats?
Answer: Male Savannahs are typically larger in size and sterile until the F5 generation or so, although the females are fertile from the F1 generation. As of 2011, breeders were noticing a resurgence in sterility in males at the F5 and F6 generations. Presumably, this is due to the higher serval percentage in C and SBT cats.