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.
Classification
Family Atelidae
* Subfamily Alouattinae
** A. palliata group
*** Coiba Island Howler, Alouatta coibensis
**** Alouatta coibensis coibensis
**** Azuero Howler Monkey, Alouatta coibensis trabeata
*** Mantled Howler, Alouatta palliata
**** Ecuadorian Mantled Howling Monkey, Alouatta palliata aequatorialis
**** Golden-mantled Howling Monkey, Alouatta palliata palliata
**** Mexican Howling Monkey, Alouatta palliata mexicana
*** Guatemalan Black Howler, Alouatta pigra
** A. seniculus group
*** Ursine Howler, Alouatta arctoidea
*** Red-handed Howler, Alouatta belzebul
*** Spix's Red-handed Howler, Alouatta discolor
*** Brown Howler, Alouatta guariba
**** Northern Brown Howler, Alouatta guariba guariba
**** Southern Brown Howler, Alouatta guariba clamitans
*** Juruá Red Howler, Alouatta juara
*** Guyanan Red Howler, Alouatta macconnelli
*** Amazon Black Howler, Alouatta nigerrima
*** Purus Red Howler, Alouatta puruensis
*** Bolivian Red Howler, Alouatta sara
*** Venezuelan Red Howler, Alouatta seniculus
*** Maranhão Red-handed Howler, Alouatta ululata
** A. caraya group
*** Black Howler, Alouatta caraya
* Subfamily Atelinae
Anatomy and physiology
, 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. This has
evolved independently from other New World monkeys due to
gene duplication. 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 2 kg heavier than females.
The hyoid of Alouatta is pneumatized -- one of the few cases of postcranial pneumaticity outside Saurischia.
Locomotion
Howler monkeys generally move quadrapedally on the tops of branches, usually grasping a branch with at least two hands or one hand and the tail at all times. They have strong
prehensile tails which are able to support the monkey's entire body weight. However, fully adult howler monkeys do not often rely on their tail for full body support whereas juveniles do so more frequently.
Behavior
Social systems
Most howler monkey species live in groups of 10 to 15 aniamls, with one to three adults males and multiple females. Mantled howlers monkeys (Alouatta palliata) are an exception, commonly living in groups of 15 to 20 individuals with more than three adult males. Unlike most New World monkeys, in which one sex remains in natal groups, juveniles of both sexes emigrate from their natal groups, such that howler monkeys could spend the majority of their adult lives in association with non-kim.
Physical 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 but physical aggression is even more rare between sexes. Group size varies by species and by location, with an approximate male to female ratio of a male to four females. Howler monkeys are also known to occasionally raid birds nests and chicken coops and consume the eggs.
Relationship with humans
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
External links
Primate Info Net Alouatta Factsheets
Howler monkey audio recording
Information about howler monkeys from Belize Zoo (photos, video and audio included)
"The Loudest Animal in the New World," Smithsonian National Zoological Park
Category:Fauna of Honduras
Category:Howler monkeys
![howler monkeys in the tree tops, Iberostar Tucan Quetzal [HD] cc](http://web.archive.org./web/20101230212608im_/http://i.ytimg.com/vi/t7s89ECJgQs/2.jpg "howler monkeys in the tree tops, Iberostar Tucan Quetzal [HD] cc")
![Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]](http://web.archive.org./web/20101230212608im_/http://cdn.wn.com/pd/73/1b/8b5bdd10e7368b9234ac784305e7_grande.jpg "Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]")
![Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]](http://web.archive.org./web/20101230212608im_/http://cdn.wn.com/pd/e2/31/d8f4ec6224304380dfa9f7761cfd_grande.jpg "Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]")
![Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]](http://web.archive.org./web/20101230212608im_/http://cdn.wn.com/pd/73/1b/8b5bdd10e7368b9234ac784305e7_thumb.jpg "Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]")
![Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]](http://web.archive.org./web/20101230212608im_/http://cdn.wn.com/pd/e2/31/d8f4ec6224304380dfa9f7761cfd_thumb.jpg "Tortuguero National Park is a National Park within the Tortuguero Conservation Area. The reserve is also included in the Humedal Caribe Noreste, a wetland of international importance under the Ramsar Convention.[1] The park is located in the Limón Province of northeastern Costa Rica. It is the third-most visited park in Costa Rica, despite the fact that it can only be reached by airplane or boat.[2]")
