Colobinae

The Colobinae are a subfamily of the Old World monkey family that includes 59 species in 10 genera, including the skunk-like black-and-white colobus, the large-nosed proboscis monkey, and the gray langurs. Some classifications split the colobine monkeys into two tribes, while others split them into three groups. Both classifications put the three African genera Colobus, Piliocolobus, and Procolobus in one group; these genera are distinct in that they have stub thumbs (Greek κολοβός kolobós = "docked"). The various Asian genera are placed into another one or two groups. Analysis of mtDNA confirms the Asian species form two distinct groups, one of langurs and the other of the "odd-nosed" species, but suggests the gray langurs are not closely related to either.

Characteristics
Colobines are medium-sized primates with long tails and diverse colorations. The coloring of nearly all the young animals differs remarkably from that of the adults.

Most species are arboreal, although some live a more terrestrial life. They are found in many different habitats of different climate zones (rain forests, mangroves, mountain forests, and savanah), but not in deserts and other dry areas. They live in groups, but in different group forms.

They are almost exclusively herbivores, predominantly nourishing themselves on leaves, flowers, and fruits. They occasionally eat insects and other small animals. To aid in digestion, particularly of hard-to-digest leaves, they have multichambered, complex stomachs. Unlike the other subfamily of Old World monkeys, the Cercopithecinae, they possess no cheek pouches.

Gestation averages six to seven months. Young are weaned at about one year and are mature at three to six years. Their life expectancy is approximately 20 years.

Classification

 * FAMILY CERCOPITHECIDAE
 * Subfamily Cercopithecinae
 * Subfamily Colobinae
 * African group
 * Genus Colobus - black-and-white colobus monkeys
 * Genus Piliocolobus - red colobus monkeys
 * Genus Procolobus - olive colobus
 * Langur (leaf monkey) group
 * Genus Trachypithecus - lutungs
 * Genus Presbytis - surilis
 * Genus Semnopithecus - gray langurs
 * Odd-nosed group
 * Genus Pygathrix - doucs
 * Genus Rhinopithecus - snub-nosed monkeys
 * Genus Nasalis - proboscis monkey
 * Genus Simias - pig-tailed langur

Hybrids
Intergeneric hybrids are known to occur within the Colobinae subfamily. In India, gray langurs (Semnopithecus spp.) are known to hybridize with Nilgiri langurs (Trachypithecus johnii).