Howler monkey

Howler monkey[1]
Black Howler Alouatta caraya
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Atelidae
Subfamily: Alouattinae
Trouessart, 1897 (1825)
Genus: Alouatta
Lacepede, 1799
Type species
Simia belzebul
Linnaeus, 1766
Species

Alouatta arctoidea
Alouatta belzebul
Alouatta caraya
Alouatta coibensis
Alouatta discolor
Alouatta guariba
Alouatta juara
Alouatta macconnelli
Alouatta nigerrima
Alouatta palliata
Alouatta pigra
Alouatta puruensis
Alouatta sara
Alouatta seniculus
Alouatta ululata

Howler monkeys (genus Alouatta monotypic in subfamily Alouattinae) are among the largest of the New World monkeys. Nine species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae. These monkeys are native to South and Central American forests. Threats to howler monkeys include human predation, habitat destruction and being captured for captivity as pets or zoo animals.

Contents

Classification

Anatomy and physiology

Male Mantled Howler, Costa Rica

Howler monkeys have a short snout, and wide-set, round nostrils. They range in size from 56 to 92 cm, excluding their tail which can be equally as long. Like many New World monkeys, they have prehensile tails. Unlike other New World monkeys, both male and female howler monkeys have trichromatic color vision.[2] This has evolved independently from other New World monkeys due to gene duplication.[3] They have a lifespan of 15 to 20 years. Howler species are dimorphic and can also be dichromatic (i.e. Alouatta caraya). Males are, on average, 1.5 to 2kg heavier than females Cite error: Closing </ref> missing for <ref> tag so neither adult males nor adults females in a group are typically related. Fighting among group members is infrequent and generally of short duration. However, serious injuries can result. Both males and females may fight with each other.[4][5] Group size varies by species and by location, with an approximate male to female ratio of a male to four females.[4]

Communication

A pair of howler monkeys vocalising

As their name suggests, vocal communication forms an important part of their social behavior. They have an enlarged basihyal or hyoid bone which helps them make their loud sound. They are considered the loudest land animal. According to Guinness Book of World Records, it can be heard clearly for 3 miles (4.8 km).

Diet and feeding

These large and slow moving monkeys are the only folivores of the New World monkeys. Howlers eat mainly top canopy leaves, together with fruit, buds, flowers, and nuts. They need to be careful not to eat too much of certain species of mature leaf in one sitting, as some of the leaves they eat contain toxins that can poison the monkey.[6] Howler monkeys are also known to occasionally raid birds nests and chicken coops and consume the eggs.[7]

Relationship with humans

Howler monkey

While seldom aggressive, howler monkeys 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 . However, the Black Howler (Alouatta caraya) is a relatively common pet monkey in contemporary Argentina due to its gentle nature, in comparison to the capuchin monkey's aggressive tendencies, in spite of its lesser intelligence as well as the liabilities meant by the size of its droppings and the males' loud vocalisation.

Alexander von Humboldt said about howler monkeys that "their eyes, voice, and gait are indicative of melancholy", while John Lloyd Stephens described those at the Maya ruins of Copán as "grave and solemn as if officiating as the guardians of consecrated ground". To the Mayas of the Classic Period, they were the divine patrons of the artisans, especially scribes and sculptors. Copán in particular is famous for its representations of Howler Monkey Gods. Two howler monkey brothers play a role in the 16th century myth of the Maya Hero Twins included in the Popol Vuh.

References

  1. ↑ Groves, C. (2005). Wilson, D. E., & Reeder, D. M, eds. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 148–152. ISBN 0-801-88221-4. OCLC 62265494. http://www.bucknell.edu/msw3. 
  2. ↑ Jacobs, G. H.; Neitz, M., Deegan, J. F., & Neitz, J. (1996). "Trichromatic colour vision in New World monkeys". Nature 382 (382): 156–158. doi:10.1038/382156a0. PMID 8700203. 
  3. ↑ Lucas, P. W., and N. J. Dominy (2003). "Evolution and function of routine trichromatic vision in primates". Evolution 57 (11): 2636–2643. PMID 14686538. 
  4. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Sussman
  5. ↑ Crockett (1997-10-02). "Family Feuds". In Ciochon, R. L., Nisbett, R. A.. Primate Anthology, The: Essays on Primate Behavior, Ecology and Conservation from Natural History. Prentice Hall. pp. 32. ISBN 9780136138457. 
  6. ↑ Glander, Kenneth E. (March 1977). "Poison in a monkey's Garden of Eden". Natural history 86: 146–151. 
  7. ↑ [1], additional text.

External links