(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.
Fox squirrels can mate all year long; however, most mating occurs in two mating seasons on from December to February and another from May until June. Females can begin to have babies at 6 months old and have one or two litters per year. Males can begin to mate at 10 to 11 months old. Female fox squirrels are pregnant for about 44 days. Average litter size is 3 young but it can range from 1 to 6 young per litter.