(of an organism or tissue) living in the absence of air or free oxygen. pertaining to or caused by the absence of oxygen.
Parakeets can breed year round if conditions are right in their environment. Normal breeding season begins early in the year and continues until fall. It is very rare to see parakeets mating, but a male and a female must mate to keep the eggs fertile.
You can make conditions favorable for a pair of birds to breed. You have to start off with a male/female pair. The birds have to be compatible and pair-bond before they will even think about mating/breeding. Parakeets should be at least 1 year old before you allow them to breed.