Howler monkey in the context of "Howler Monkey Gods"

The Usumacinta River (Spanish pronunciation: [usumaˈsinta]; named after the howler monkey) is a river in southeastern Mexico and northwestern Guatemala. It is formed by the junction of the Pasión River, which arises in the Sierra de Santa Cruz (in Guatemala) and the Salinas River, also known as the Rio Chixoy, or the Rio Negro, which descends from the Sierra Madre de Guatemala. It defines part of the border between Guatemala and the Mexican state of Chiapas, then continues its northwesterly course, meandering through the Mexican state of Tabasco to the Gulf of Mexico.

The Usumacinta River enters Mexican territory in the state of Tabasco and across the Cañón del Usumacinta (Usumacinta Canyon) ecological reserve, forming impressive canyons along its route. Passing the canyon called "Boca del Cerro", Tenosique, the Usumacinta goes into the plain of Tabasco.

The Atelidae are one of the five families of New World monkeys now recognised. It was formerly included in the family Cebidae. Atelids are generally larger monkeys; the family includes the howler, spider, woolly, and woolly spider monkeys (the latter being the largest of the New World monkeys). They are found throughout the forested regions of Central and South America, from Mexico to northern Argentina.

The Atelinae are a subfamily of New World monkeys in the family Atelidae, and includes the various spider and woolly monkeys. The primary distinguishing feature of the atelines is their long prehensile tails, which can support their entire body weight.

Atelines live on the American continent from southern Mexico through central Brazil and Bolivia. Diurnal and arboreal, they move speedily and acrobatically through the trees using their tails. Atelines, along with the related howler monkeys, are the largest of the New World monkeys. They live in groups, show amicable intergroup relations, and can coalesce into large aggregations for extended periods of time.

The mantled howler (Alouatta palliata) is a species of howler monkey, a type of New World monkey, from Central and South America. It is one of the monkey species most often seen and heard in the wild in Central America. It takes its "mantled" name from the long guard hairs on its sides.

The mantled howler is one of the largest Central American monkeys, and males can weigh up to 9.8 kg (22 lb). It is the only Central American monkey that eats large quantities of leaves; it has several adaptations to this folivorous diet. Since leaves are difficult to digest and provide less energy than most foods, the mantled howler spends the majority of each day resting and sleeping. 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.