I think Travis has a point to an extent. Yes Desert females have not yet been able to have a fertile clutch, but who is to say that this will remain true. Special conditions could be the only thing needed. I do not think there has been a whole species or type of animal that has been infertile in its entirety but the Desert Ball python could prove to be one of these animals. I do not plan on getting into them because of there infertility problem but I just feel like it may still be possible to get a fertile clutch, but it is also just as possible that they never have a fertile clutch. Who knows we will just have to wait and see.