No egg has ever hatched. Yesterday I found all the remaining 5 eggs (the hen laid some more eggs) were pushed out of the nest by the cock. I was surprised to see him doing it. I always thought it was the hen who pushed the "expired" eggs out. The cock might be frustrated to see the hen staying in the nest for months and left him alone outside. Only 1 out of the 5 eggs had a lifeless chick in there.
I have just removed the nest from the cage this morning. The hen needs some rest after all the sitting in the last a few months.
I might try to breed them again in a month or two.
