Of course, interfertility is not the be-all and end-all of determining whether two taxa are conspecific; although some "lumpers" do include all small cats within the one genus of Felis, the existence of bengal cats - derived from Prionailurus bengalensis x Felis sylvestris catus breedings - and savannah cats - derived from Leptailurus serval x Felis sylvestris catus breedings - has never to my knowledge been used to suggest that P.bengalensis, L.serval and F.sylvestris should *all* be included within F.sylvestris 