Reproduction
Males usually reach sexual maturity at about 3-3.5 years old, while females reach it at about two years old. Females approaching estrous can be easily identified because of the swelling and bright red coloration of the genital area. This signals to males that the given female is ready for mating. Moreover, just prior to mating, males will use their fingers to probe the female's birth canal. This is immediately followed by sniffing the area because estrogen and progesterone can be detected by this method, further helping the male conclude if the female is indeed ready to breed.
Gestation is about 6 months for colobus monkeys and one female has about 1-2 new-born every two years. Parental care is intense and often, the role is shared by multiple females of the group. It is observed that about 76% of offspring are born between September and December. Infanticide has also been noted on occasion when a new male joins a given group that has infants.
Research has suggested that the ability for dietary expansion, which consuming charcoal partly allows, explains the higher birth rates and densities due to resource availability. Birth rates for those living in mangroves are higher than colobus monkeys living in coral rag forests.
There are higher birthing rates between October-December for colobines on Uzi Island and then January-February for those in Kiwengwa, located on the eastern side of the main island. Infant mortality can be significantly high with half of the infants born not reaching more than six months of age. The birth rates themselves, however, are actually decreased in comparison to mainland colobus monkeys and interbirth intervals are longer as well. Research has suggested that this is a consequence of disturbed habitats in which mainland colobi are not so affected.
Read more about this topic: Zanzibar Red Colobus
Famous quotes containing the word reproduction:
“The atmosphere parents wish to create when talking with children about birth and reproduction is warm, honest, and reassuring, one that tells children they are free to ask questions as often as they need to, and you will answer them as lovingly as you know how.”
—Joanna Cole (20th century)
“Although Samuel had a depraved imagination—perhaps even because of this—love, for him, was less a matter of the senses than of the intellect. It was, above all, admiration and appetite for beauty; he considered reproduction a flaw of love, and pregnancy a form of insanity. He wrote on one occasion: “Angels are hermaphrodite and sterile.””
—Charles Baudelaire (1821–1867)
“The chief function of the city is to convert power into form, energy into culture, dead matter into the living symbols of art, biological reproduction into social creativity.”
—Lewis Mumford (1895–1990)