Interesting Creatures in Guyana…The Spider Monkey (Ateles geoffroyi)

Jun 22, 2008 News

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Regarded as the New World Monkeys of the family Atelidae, Spider Monkeys (Ateles geoffroyi) are believed to be the most intelligent monkey species in the world.
In fact, a recent comparative intelligence evaluation gives Spider Monkeys a value slightly above gorillas, leading to the conclusion that they are relatively more clever.
Well known as occupants of South American, of which several are inhabitants of Guyana, Spider Monkeys are said to be easily identifiable by their disproportionately long, spindly limbs, a feature which has inspired their common name.

They are also said to have deftly prehensile tails which may measure up to 89 centimetres (cm) and are covered with highly flexible hairless tips complete with skin grooves similar to fingerprints.
Adults reportedly reach an average body length of 50 cm and a weight of 6.4 kilograms.
And like a few other monkey species, their arms are very thin and long with legs that are on the shorter end thus causing them to walk with their arms practically dragging on the ground.
Typically they just stand and walk on two feet and if they encounter balancing problems they are able to grab onto their tail to help them.
Their hands resemble their arms since they are also long and skinny.
Another interesting feature which makes Spider Monkeys more recognisable is the fact that their nostrils are very far apart.
Also, these monkeys which have small heads also possess hook-like, narrow, thumbless hands with fingers that are elongated and curved.
Their hair is said to be coarse ranging in colour from ruddy gold to brown and black and their hands and feet are usually black.
Forming loose groups of about 15 to 25 individuals, Spider Monkeys are highly agile.
It is said that during the day they break up into smaller subgroups of two to eight individuals – a social structure which is evident in some other monkey species.
Reports are that the size of subgroups and the degree to which they will avoid each other is determined by food competition and the risk of predation.
There are reports that the postures and stances of a monkey serve to communicate their intentions and observations. Examples include the postures of sexual receptivity or an attack posture.
When a monkey is approached it will climb to the end of the branch it is on and shake it vigorously in an attempt to scare the possible threat away.
These animals can shake the branches with their feet, hands or a combination while hanging from their tail.
They may also scratch their limbs or bodies with various parts of their hands and feet.
It is said that male spider monkeys and occasionally females will growl menacingly at the approach of a human. Reports are that if a pursuer continues to advance the monkey will often break off a tree limb weighing up to 10 pounds and drop it. They are also well known for defecating and urinating towards the threatening object.
And since they are diurnal, they spend the night sleeping in carefully selected trees. Groups are thought to be directed by a lead female that is responsible for planning an efficient route for the day’s feeding activities.
These monkey species are also said to mate year round with the female choosing a male from her group.
Both genders are said to sniff their mates to check their readiness for copulation, a process which is called anogenital sniffing. On average, only one offspring at a time is produced by each female and the gestation period can range from 226 to 232 days.
A mother Spider Monkey will carry a newborn around her belly for no more than the first month. After this the young monkey travels on the lower back of the mother, wrapping its tail around her.
Female spider monkeys are very protective of their young and are generally good mothers. They have been seen grabbing their young and putting them on their backs for protection as well as to help them navigate from tree to tree. They also aid in the crossing from tree to tree by pulling branches closer together to allow easier crossing for their more independent young. Mothers will also groom their young on occasion. For the first six to ten months of a young Spider Monkey’s life it relies completely on its mother. However, the male Spider Monkeys have nothing to do with the raising of offspring.
These monkeys’ diet consists of about 90 per cent fruits and nuts. It is believed that they can live for long periods of time on only one or two different kinds of fruits and nuts. They eat the fruits of many big forest trees, and because they swallow fruits whole, the seeds are eventually passed out as tree fertilizer.
If their food supply is low they can resort to eating insects, bark or rotting forest, and honey.
And since they are said to require large tracts of undisturbed forest and specialise on ripe fruits, spider monkeys may be considered an indicator species. However, they are threatened by habitat destruction through continued growth in South American agriculture.
But although their lifespan in the wild is about 27 years, they are said to be critically endangered which means they are facing an extremely high risk of extinction.
(Source: The Wikepedia Free Online Encyclopedia)

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