African Greys are not dimorphic birds, i.e., it is difficult to differentiate male from female with the naked eye. The sex of a parrot can be determined with certainty by genetic determination (PCR) from a blood sample or a freshly plucked feather. Sex can also be determined by surgical intervention (endoscopy), in which the gonads are directly exposed. If your baby comes from the Psittacus Catalonia breeding center, you will receive it already sexed by PCR and with the corresponding certificate.