Gray-handed Night Monkey
Encyclopedia
The gray-handed night monkey (Aotus griseimembra) is a species of night monkey
formerly considered a subspecies of Gray-bellied night monkey
of the family Aotidae. Its range consists of parts of Colombia
and Venezuela
. The exact classification of the gray-handed night monkey is uncertain. While some authors consider it a subspecies of the gray-bellied night monkey, A. lemurinus, other authors consider it a separate species, A. griseimembra.
In Colombia, its range consists of the northern portion from the Sinú River
(or perhaps further east) to the Venezuelan border, including the Sierra Nevada de Santa Marta
and the Magdalena River
, Cauca River
and Sao Jorge River valleys. In Venezuela, it is found to the west and south of Maracaibo
.
The gray-handed night monkey is a relatively small monkey, with males weighing approximately 1009 grams (35.6 oz) and females weighing about 923 grams (32.6 oz). It has short, tight fur. The fur on the back ranges from gray-brown to reddish-brown. The belly is yellowish. The hair on the back of the hands and feet is the color of light coffee
with darker hair tips, a key distinguishing feature from other A. lemurinus subspecies.
The gray-handed night monkey is arboreal and nocturnal. It and the other members of the genus Aotus are the only nocturnal monkeys. Laboratory experiments indicated lower levels of activity even in lighting conditions consistent with a full moon
. It is found in several types of forest, including secondary forest
and coffee
plantations, although one study indicated a preference for highly diverse forest. It lives in small groups of between two and six monkeys, most typically two to four, consisting of an adult pair and one infant and several juveniles and/or subadults. Groups are territorial, and groups occupy ranges that overlap only slightly. One study found a population density of 1.5 monkeys per square kilometer, while another found a density of 150 monkeys per square kilometer. The latter figure occurred in a forest remnant that had served as a refuge, which may account for the exteremely high density.
In common with other night monkeys, the gray-handed night monkey is one of the few monogamous monkeys. The monogamous pair generally gives birth to a single infant each year, although twins occasionally occur. The gestation
period is about 133 days. The father carries the infant from the time it is one or two days old, passing it to the mother for nursing
. Average interbirth interval for the mother is 271 days.
The gray-handed night monkey is listed as "vulnerable" by the International Union for Conservation of Nature (IUCN). It is believed to be particularly threatened in Colombia. This is in part due to habitat loss, but also because many were captured in the 1960s and 1970s for malaria
research.
Night monkey
The night monkeys, also known as the owl monkeys or douroucoulis, are the members of the genus Aotus of New World monkeys . They are widely distributed in the forests of Central and South America, from Panama south to Paraguay and northern Argentina...
formerly considered a subspecies of Gray-bellied night monkey
Gray-bellied Night Monkey
The gray-bellied night monkey , also called the lemurine owl monkey, is a small New World monkey of the family Aotidae...
of the family Aotidae. Its range consists of parts of Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
and Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
. The exact classification of the gray-handed night monkey is uncertain. While some authors consider it a subspecies of the gray-bellied night monkey, A. lemurinus, other authors consider it a separate species, A. griseimembra.
In Colombia, its range consists of the northern portion from the Sinú River
Sinú River
Sinú River , is a river in northwestern Colombia that flows mostly through the Córdoba Department and into the Caribbean. The river is the third most important river after the Magdalena River and the Cauca River in the Caribbean Region. It is born in the Antioquia Department, flowing south to north...
(or perhaps further east) to the Venezuelan border, including the Sierra Nevada de Santa Marta
Sierra Nevada de Santa Marta
The Sierra Nevada de Santa Marta is an isolated mountain range apart from the Andes chain that runs through Colombia. Reaching an altitude of 5,700 metres above sea level just 42 km from the Caribbean coast, the Sierra Nevada is the world's highest coastal range...
and the Magdalena River
Magdalena River
The Magdalena River is the principal river of Colombia, flowing northward about through the western half of the country. It takes its name from the biblical figure Mary Magdalene. It is navigable through much of its lower reaches, in spite of the shifting sand bars at the mouth of its delta, as...
, Cauca River
Cauca River
The Cauca River is a river in Colombia that lies between the Occidental and Central cordilleras. Born in southwestern Colombia near the city of Popayán, it joins the Magdalena River near Pinillos in Bolívar Department, and the combined river eventually flows out into the Caribbean Sea. It has a...
and Sao Jorge River valleys. In Venezuela, it is found to the west and south of Maracaibo
Maracaibo
Maracaibo is a city and municipality located in northwestern Venezuela off the western coast of the Lake Maracaibo. It is the second-largest city in the country after the national capital Caracas and the capital of Zulia state...
.
The gray-handed night monkey is a relatively small monkey, with males weighing approximately 1009 grams (35.6 oz) and females weighing about 923 grams (32.6 oz). It has short, tight fur. The fur on the back ranges from gray-brown to reddish-brown. The belly is yellowish. The hair on the back of the hands and feet is the color of light coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
with darker hair tips, a key distinguishing feature from other A. lemurinus subspecies.
The gray-handed night monkey is arboreal and nocturnal. It and the other members of the genus Aotus are the only nocturnal monkeys. Laboratory experiments indicated lower levels of activity even in lighting conditions consistent with a full moon
Full moon
Full moon lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. More precisely, a full moon occurs when the geocentric apparent longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun.Lunar eclipses can only occur at...
. It is found in several types of forest, including secondary forest
Secondary forest
A secondary forest is a forest or woodland area which has re-grown after a major disturbance such as fire, insect infestation, timber harvest or windthrow, until a long enough period has passed so that the effects of the disturbance are no longer evident...
and coffee
Coffee
Coffee is a brewed beverage with a dark,init brooo acidic flavor prepared from the roasted seeds of the coffee plant, colloquially called coffee beans. The beans are found in coffee cherries, which grow on trees cultivated in over 70 countries, primarily in equatorial Latin America, Southeast Asia,...
plantations, although one study indicated a preference for highly diverse forest. It lives in small groups of between two and six monkeys, most typically two to four, consisting of an adult pair and one infant and several juveniles and/or subadults. Groups are territorial, and groups occupy ranges that overlap only slightly. One study found a population density of 1.5 monkeys per square kilometer, while another found a density of 150 monkeys per square kilometer. The latter figure occurred in a forest remnant that had served as a refuge, which may account for the exteremely high density.
In common with other night monkeys, the gray-handed night monkey is one of the few monogamous monkeys. The monogamous pair generally gives birth to a single infant each year, although twins occasionally occur. The gestation
Gestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
period is about 133 days. The father carries the infant from the time it is one or two days old, passing it to the mother for nursing
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
. Average interbirth interval for the mother is 271 days.
The gray-handed night monkey is listed as "vulnerable" by the International Union for Conservation of Nature (IUCN). It is believed to be particularly threatened in Colombia. This is in part due to habitat loss, but also because many were captured in the 1960s and 1970s for malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
research.