(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.
The courting rituals of giraffes involve the chin resting of the male on the back of the female. While giraffes have no set mating season it will usually take place during the rainy season. This is because they are less stressed out and because they have plenty of food to consume. When food supplies are very low then they have to kick into survival mode and they are less likely to take part in reproduction.