(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.
For crocodiles the mating season usually will begin in August or September. Females are ready to mate when they are about 10 years of age. Males are ready to mate around 16 years of age.