Lastly I'm going to talk more on their reproduction.
Previously a problem to reproduction, pandas lose their interest in mating once in captivity. This has led some scientists to try extreme methods such as showing pandas videos of mating pandas and giving male pandas Viagra. The primary reproduction method had been artificial insemination. Only recently have researchers begun to have success with captive breeding programs and have determined that pandas have comparable breeding to some populations of the American Black Bear, a thriving bear family. The current reproductive rate is considered one young every two years.
Pandas reach sexual maturity between the ages of 4 and 8, and may be reproductive until age 20. The mating season takes place between March and May, when a female goes into her estrous cycle which lasts for 2 or 3 days and only occurs once a year. During this time, two to five males can compete for one female; the male with the highest rank gets the female[dubious – discuss]. When mating, the female is in a crouching, head-down position as the male mounts her from behind. Copulation time is short, ranging from thirty seconds to five minutes, but the male may mount her repeatedly to ensure successful fertilization. The whole gestation period ranges from 95 to 160 days. Baby pandas weigh only 90 to 130 grams (3.2 to 4.6 ounces), which is about 1/900 of the mother's weight. Usually, the female panda gives birth to one or two panda cubs. Since baby pandas are born very small and helpless, they need the mother's undivided attention, so she is able to care for only one of her cubs. She usually abandons one of her cubs, and it dies soon after birth. At this time, scientists do not know how the female chooses which cub to raise, and this is a topic of ongoing research. The father has no part in helping raise the cub.
When the cub is first born, it is pink, furless, and blind. A panda cub is also extremely small, and it is difficult for the mother panda bear to protect it because of the baby's size. It nurses from its mother's breast 6 to 14 times a day for up to 30 minutes at a time. For three to four hours, the mother may leave the den to feed, which leaves the panda cub defenseless. One to two weeks after birth, the cub's skin turns gray where its hair will eventually become black. A slight pink color may appear on the panda's fur, as a result of a chemical reaction between the fur and its mother's saliva. A month after birth, the color pattern of the cub's fur is fully developed. A cub's fur is very soft and coarsens with age. The cub begins to crawl at 75 to 90 days; mothers play with their cubs by rolling and wrestling with them. The cubs are able to eat small quantities of bamboo after six months, though mother's milk remains the primary food source for most of the first year. Giant Panda cubs weigh 45 kg (99.2 pounds) at one year, and live with their mothers until they are 18 months to two years old. The interval between births in the wild is generally two years.
There are some ways which we can help to prevent the extinction of pandas. Some examples are, stop destroying their habitats, stop poaching and hunting Giant Pandas and by telling the whole world about this matter, we can help to save the Giant Pandas.
Monday, March 30, 2009
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment