Howler Monkey

Howler monkeys
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Superfamily: Platyrrhini Family: Atelidae Subfamily: Alouattinae Genus: Alouatta
Species
A. palliata or A. villosa' A. pigra A. seniculus A. belzebul A. fusca A. caraya

The howler monkeys (genus Alouatta monotypic in subfamily Alouattinae) are among the largest of the New World monkeys. Six species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae.

Howler monkeys range in size from 56 to 92cm, excluding their tail which can be as long again. Like many New World monkeys, they have prehensile tails. They have a lifespan of 15 to 20 years. These monkeys are native to South and Central American forests. Threats to howler monkeys include being hunted for food and export.

As their name suggests, vocal communication forms an important part of their social behaviour. Specifically, the name comes from their distinctive loud barking whoop they make, which can be heard over considerable distances. They have an enlarged basihyal or hyoid bone which helps them make their loud sound. Unlike other New World monkeys, both male and female howler monkeys have trichromatic colour vision.

Their prehensile tails are strong enough to support the monkey's entire body weight, although they seldom do so. The first 2 fingers of each hand are set apart and are opposable to the other three. They very seldom leave the trees.

The large slow moving monkeys are the only folivores of the New World monkeys. Howlers eat mainly top canopy leaves, together with fruit, buds, and flowers. They move quadrapedally and do not brachiate, usually holding on to a branch with at least two hands or one hand and the tail at all times.

The Central American howlers, known as Mantled Howler Monkeys, are classified either as Alouatta palliata or Alouatta villosa. They live in groups of usually about 18 individuals.

Howlers and humans

Alexander von Humboldt said that "their eyes, voice, and gait are indicative of melancholy", while John Lloyd Stephens described those at the ruins of Copan as "grave and solemn as if officiating as the guardians of consecrated ground".

While seldom agressive, they do not take well to captivity and are of surly disposition, and hence are the only monkey in their forests not made a pet by the Native Americans.

• ORDER PRIMATES
  • Suborder Strepsirhini: non-tarsier prosimians
  • Suborder Haplorhini: tarsiers, monkeys and apes
    • Family Tarsiidae: tarsiers
    • Superfamily Platyrrhini
      • Family Cebidae:
      • Family Atelidae
        • Subfamily Aotinae
        • Subfamily Callicebinae
        • Subfamily Pitheciinae
        • Subfamily Alouattinae
          • Red-handed Howler Monkey, Alouatta belzebul
          • Black Howler Monkey, Alouatta caraya
          • Coiba Island Howler Monkey, Alouatta coibensis
          • Brown Howler Monkey, Alouatta fusca
          • Mantled Howler Monkey, Alouatta palliata
          • Guatemalan Howler Monkey, Alouatta pigra
          • Red Howler Monkey, Alouatta seniculus
        • Subfamily Atelinae
    • Superfamily Catarrhini
      • Family Cercopithecidae: Old World monkeys
      • Family Hylobatidae: gibbons
      • Family Hominidae: great apes and humans