The Mantled Howler Monkey is a type of New World monkey from Central and South America in Colombia, Costa Rica, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Panama and Peru. They live in several different types of forest, including secondary forest and semi-deciduous forest but are found in higher densities in older areas of forest and in areas containing evergreen forest. They eat large quantities of leaves; it has several adaptations to this folivorous diet. They possess large salivary glands that help break down the leaf tannins. The leaves and fruit from Ficus trees tend to be their preferred source but flowers can also make up a significant portion of the diet. They satisfy their water needs by drinking from tree holes during the wet season and sourcing water trapped in bromeliads. The fact that they rely so heavily on a low energy food sources drives much of their behaviour--for example, howling to locate other groups and spending a large portion of the day resting. They are primarily black except for a fringe of yellow or golden brown guard hairs on the flanks of the body earning the common name "mantled" howler monkey. The infant's fur is silver at birth, but turns pale or gold after a few days and then darkens until the infant takes on the adult coloration at about 3 months old. They are one of the largest Central American monkeys, and males can weigh up to 9.8 kg while females generally weigh between 3.1 and 7.6 kg. They live in groups of 10 to 20 members, generally 1 to 3 adult males and 5 to 10 adult females, but some groups have over 40 members. Grooming activity in the mantled howler is infrequent and has been shown to reflect social hierarchy, with dominant individuals grooming subordinates. Males outrank females, and younger animals of each gender generally have a higher rank than older animals. Higher-ranking animals get preference for food and resting sites, and the alpha male gets primary mating rights. Females become sexually mature at 36 months, males at 42 months. They undergo a regular estrus cycle, with an average duration of 16.3 days, and display sexual skin changes. The copulatory sequence begins when a receptive female approaches a male and engages in rhythmic tongue flicking. The male responds with the same tongue movements before the female turns while elevating her rump, which allows for mating to begin. The gestational period is 186 days; births can occur at any time of year. The infant is carried under its mother, clinging to its mother's chest, for the first 2 or 3 weeks of its life. After that, it is carried on its mother's back. The male mantled howler has an enlarged hyoid bone, a hollow bone near the vocal cords, which amplifies the calls made by the male, and is the reason for the name "howler". Howling allows the monkeys to locate each other without expending energy on moving or risking physical confrontation. They also use non-vocal communication, such as "urine rubbing" when in a distressful social situation. They rub their hands, feet, tail and/or chest with urine and mark their scent by rubbing its throat on branches. Genital displays are used to indicate emotional states, and group members shake branches, which is apparently a playful activity. The mantled howler is usually indifferent to the presence of humans. However, when it is disturbed by people, it often express its irritation by urinating or defecating on them. It can accurately hit its observers despite being high in the trees. They are regarded as vulnerable and their numbers are adversely affected by rainforest fragmentation which has caused forced relocation of groups to less habitable regions, as well as deforestation and capture for the pet trade. They are protected from international trade under Appendix I of the Convention on International Trade in Endangered Species.