LIONS
The average gestation period is around 110 days,
the female giving birth to a litter of one to four
cubs in a secluded den (which may be a thicket, a reed-bed, a cave or some other
sheltered area) usually away from the rest of the pride. She will often hunt by
herself while the cubs are still helpless, staying relatively close to the thicket or
den where the cubs are kept. The cubs themselves are born blind—their eyes do
not open until roughly a week after birth. They weigh 1.2–2.1 kg (2.6–4.6 lb) at
birth and are almost helpless, beginning to crawl a day or two after birth and
walking around three weeks of age. The lioness moves her cubs to a new den site
several times a month, carrying them one by one by the nape of the neck, to
prevent scent from building up at a single den site
and thus avoiding the attention of predators that
may harm the cubs.
DOG
Dogs bear their litters roughly 56 to 72 days after
fertilization, with an average of 63 days, although
the length of gestation can vary. An average litter consists of about six puppies,
though this number may vary widely based on the breed of dog. In general, toy
dogs produce from one to four puppies in each litter, while much larger breeds
may average as many as twelve.
HORSES
Some dog breeds have acquired traits through selective breeding that interfere
with reproduction. Male French Bulldogs, for instance, are incapable of mounting
the female. For many dogs of this breed, the female must be artificially
inseminated in order to reproduce.
Gestation lasts for approximately 335–340 days[42] and usually results in one
foal. Twins are rare.[43] Horses are a precocial species, and foals are capable of
standing and running within a short time following birth.[44]
Horses, particularly colts, sometimes are physically capable of reproduction at
about 18 months, but domesticated horses are rarely allowed to breed before the
age of three, especially females. Horses four years old are considered mature,
although the skeleton normally continues to develop until the age of six;
maturation also depends on the horse's size, breed, sex, and quality of care. Also,
if the horse is larger, its bones are larger; therefore, not only do the bones take
longer to actually form bone tissue, but also the epiphyseal plates are also larger
and take longer to convert from cartilage to bone. These plates convert after the
other parts of the bones, and are crucial to development.
BABOONS
Females typically give birth every other year, usually to a single infant, after a six
month gestation. The young baboon weighs approximately one kilogram and has
a black epidermis when born. The females tend to be the primary caretaker of the
young, although several females will share the duties for all of their offspring.
After about one year, the young animals are weaned. They reach sexual maturity
in five to eight years. Baboon males leave their birth group, usually before they
reach sexual maturity, whereas females are philopatric and stay in the same
group their whole life.