Black-Headed Spider Monkey

## Description

The black-headed spider monkey (Ateles fusciceps ) is a type of New World monkey, from Central and South America. It is found in Colombia, Ecuador, and Panama. Although primatologists such as Colin Groves (1989) follow Kellogg and Goldman (1944) in treating A. fusciceps as a separate species, other authors, including Froelich (1991), Collins and Dubach (2001) and Nieves (2005) treat it as a subspecies of Geoffroy's spider monkey.

The two subspecies are:

* Ateles fusciceps fusciceps - northwestern Ecuador.
* Ateles fusciceps rufiventris - southwest Colombia to eastern Panama.

A. f. fusciceps lives in tropical and subtropical humid forests between 100 and 1,700 metres (330 and 5,580 ft) above sea level. It lives in population densities of 1.2 monkeys per square kilometer. A. f. rufiventris lives in dry forests, humid forests and cloud forests, and can live up to 2,000 to 2,500 metres (6,600 to 8,200 ft) above sea level.

A. f. fusciceps has a black or brown body and a brown head. A. f. rufiventris is entirely black with some white on its chin. The black-headed spider monkey is one of the larger New World monkeys. The head and body length, excluding tail, typically ranges between 39.3 and 53.8 cm (15.5 and 21.2 in). The prehensile tail is between 71.0 and 85.5 cm (28.0 and 33.7 in). On average, males weigh 8.89 kilograms (19.6 lb) and females weigh 8.8 kilograms (19 lb). The brain weighs 114.7 g (4.05 oz).

The black-headed spider monkey is arboreal and diurnal. It moves by climbing and brachiation. When mating, females may consort with a male for up to three days, or else mate with several males. Mating occurs with the male and female face to face, and can last for five to 10 minutes. The gestation period is between 226 and 232 days. The infant rides on its mother's back for 16 weeks, and is weaned at 20 months. Females attain sexual maturity at 51 months; males at 56 months. Females give birth every three years.

The black-headed spider monkey is considered to be endangered by the International Union for Conservation of Nature (IUCN) due to an estimated population loss of more than 50% over 45 years (2018-2063), from hunting and human encroachment on its range of habitation.

Captive black-headed spider monkeys have been known to live more than 24 years.

## Appearance

The Black-headed spider monkey is native to Central and South America. This primate belongs to the group of New World monkeys. This species is composed of two sup-species, differing in their color pattern: Brown-headed spider monkeys, which exhibit brownish-black overall fur and a brown head; and Colombian spider monkeys that are totally black, displaying only a few white patches on their chin. The Black-headed spider monkeys are excellent climbers and have a strong grip due to lacking a thumb.

## Distribution

The natural range of these animals covers some parts of Central and South America. While the Brown-headed spider monkeys are generally found in Ecuador (and possibly, in Columbia), the Colombian black spider monkeys occupy a territory from south-western Colombia to eastern Panama. Both of these sub-species live in dry forests as well as humid and cloud forests. Populations in Ecuador are most frequently found in wetter forests such as tropical and subtropical humid forests.

## Behavior

The Black-headed spider monkeys are diurnal, mainly arboreal and very social animals. These primates are known to form large fission-fusion groups of 20 - 100 monkeys, composed of multiple males and females. When feeding, these groups split into smaller sub-groups. Spending the majority of their time in trees, they rarely descent to the ground. When travelling among trees, they swing on all of their four legs. When moving along branches, they usually walk in an upright position. These agile animals are excellent leapers, capable of taking long leaps of up to 9 m (30 ft.), when moving between branches. They communicate through vocalizations such as a high-frequency whinny.

## Diet

The Black-headed spider monkeys are herbivores (folivores and frugivores), they primarily feed upon ripe fruits and leaves, supplementing their usual diet with occasional nuts, seeds, insects, and eggs.

## Reproduction

Little is known about the mating behavior of Black-headed spider monkeys. It is known, however, that when mating, females may stay with a male for around three days and may mate with several males. It means that this species may exhibit either polygynandrous (promiscuous) (both males and females breed with multiple mates) or polyandrous (one female mates with several males in a breeding season) mating systems. All spider monkeys are able to breed at any time of the year. Females usually produce offspring at intervals of 3 years. The gestation period lasts between 226 and 232 days, after which a single infant is born. The newborn baby will ride the back of its mother until 16 weeks old. Weaning occurs at 20 months of age. After reaching adolescence, females leave their natal group, whereas males continue living with the group throughout their lives. The age of sexual maturity is 51 months old in females and 56 months old in males.

## Population

### Population threats

The Black-headed spider monkeys are nowadays threatened by deforestation, which negatively affect the overall population of this species. Although some populations still inhabit partially logged forests, hardly any group can be found in areas, where the rainforest habitat is totally wiped out. Additionally, localized threats include hunting for food.

### Population number

The IUCN Red List and other sources don’t provide the number of the Black-headed spider monkeys’ total population. According to the Tropical Conservation Science resource, the total population of the Brown-headed spider monkey subspecies is around 250 individuals in northwestern Ecuador. Overall, Black-headed spider monkeys are classified as Critically Endangered (CR) and their numbers are decreasing.

## Fun Facts for Kids

When moving around, these primates use all of their four legs. They also use their tail as a fifth limb, helping them to hang onto tree branches. These unique habits give the species of their genus their common name - spider monkeys.

They exhibit a prehensile tail, which, as mentioned earlier, acts as an extra limb, allowing them to move between tree branches while collecting food with their hands.

Throughout their lives, these animals hardly ever descent onto the ground, remaining high in the tree tops.

When various troops of these primates gather in once place, the animals greet each other by hugging, which helps avoid undesirable aggression and conflicts.

As diurnal animals, spider monkeys sleep by night in large groups. Their sleeping sites are situated in trees, where the monkeys are protected from local predators such as jaguars, pumas, ocelots or large snakes.

## References

https://animalia.bio/black-headed-spider-monkey