◾ In case you have been reading up or researching on Savannahs, you are most likely to have encountered terms like F1 generation, along with F2, F3, going on to F6. These figures are filial numbers, referring to each progressive generation of the Savannah.
◾ Thus, a cat born out of crossing a serval and domestic cat becomes a first generation or an F1 Savannah. This cat is considered to be between 50% and up to 75% serval.
◾ The next generation, i.e., F2, is created by breeding an F1 Savannah female with a male Savannah. Remember, the cats born in this litter will have a serval grandparent and will, therefore, be 25% to 37.5% serval.
◾ The F3 generation has a serval great grandparent, and is born to an F2 female, with a Savannah male as the father. An F3 Savannah will be about 12.5% serval.
◾ Future generations like the F4, F5, F6, and F7 are bred in a similar manner, with the serval influence diminishing to a great extent. Thus, the later generations of the Savannah are more or less similar to domestic cats rather than their wild ancestor.
◾ Being hybrids, Savannahs display certain characteristics associated with hybrid inviability. This results in male Savannahs being sterile under the F5 generation, whereas the females exhibit normal fertility from the F1 generation.