(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.
Lemur reproduction is extremely seasonal and quick. The mating season occurs from mid-April to June; female lemurs are in estrus, or fertile, for less than one day. This fast-paced biological clock makes lemur reproduction precarious.