Ateles paniscus
black spider monkey

Black spider monkeys are native to South America, north of the Amazon River. Specifically, they can be found in Brazil, French Guiana, Guyana, and Suriname. Small populations have been studied in Peru and Bolivia as well. In Guyana, they do not travel farther west than the Essequibo River. (McFarland Symington, 1988; Mittermeier, et al., 2009; Painter, et al., 1998)

Black spider monkeys can be found in dense forest habitats that are isolated from human populations. They spend a majority of their time in the middle to upper regions of the forest canopy and one study reported that they spend about 90% of their time in the upper canopy. Preferred habitat typically includes forests with canopy heights exceeding 25 m. Forest habitats bordering large rivers tend to have low population densities, possibly due to increased hunting pressure in these locations. (Mittermeier, et al., 2009; Painter, et al., 1998)

Black spider monkeys exhibit little variation in appearance, however, males are slightly larger than females. Males have an average head-body length (length of animal, excluding tail) of 54.5 cm; females have an average head-body length of 54.0 cm. Males and females have average weights of 9.11 kg and 8.44 kg, respectively. (Bearder, et al., 2007; Mittermeier, et al., 2009; Smock, 2008)

Black spider monkeys have small heads, relative to their bodies. They also have long arms and legs, and a tail that helps them balance while moving through the forest canopy. Excluding the face, hands, and feet, they are covered in jet-black hair that is longer than that found on a typical primate. (Bearder, et al., 2007; Mittermeier, et al., 2009; Smock, 2008)

Black spider monkeys initiate courtship by wrestling and playing with members of the opposite sex. This behavior often includes vocalizations like growling and heavy panting along with head-shaking. When females are in estrus, males smell and lick a potential mate's genital region. Females identify their mate choice by sitting on a specific male's lap. If her chosen mate is not immediately responsive, females leave and then repeat the action minutes later. Once a response is received, females remain sitting. Her mate then grabs her chest and wraps his legs on top of hers, placing his feet between her thighs. Females may select a single mate during estrus or mate with three to four different males per day during each breeding cycle. Black spider monkeys are polygynandrous, as males and females have multiple breeding partners during each breeding period. (Mittermeier, et al., 2009)

Relative to other primates, black spider monkeys reproduce very slowly, mating once every 3 to 4 years. Gestation typically lasts for 7.5 months, resulting in a maximum of four offspring that have an average weight of 452.5 g. Significantly more females than males are born each cycle. Black spider monkeys are independent by 15 to 18 months and reach sexual maturity around 4 to 5 years old. After reaching sexual maturity, males often remain members of their natal group. Females, however, leave to find potential mates, and return to their natal group to give birth and possibly mate with males from their natal group. Finally, black spider monkey mothers tend to invest more in male offspring than female offspring, which might affect a female's ability to leave once mature. (Lindenfors, 2002; Mittermeier, et al., 2009; Symington, 1987; Symington, 1988)

Black spider monkeys spend much of their young lives with their mother. For the first 2 to 3 months of life, newborns cling to, and wrap their tails around their mother's body, which continues until 4 to 5 months of age. From 6 to 9 months of age, young tend to ride on their mother's backs. While still spending most of their time in the presence of their mother (>90%), they begin to explore their environment independently at 10 months old. For the next 3 months they become increasingly independent, but tend to stay within about 5 m of their mother while feeding and resting on their own. Between 15 and 18 months old, they begin to travel without their mother's help. (Symington, 1988; van Roosmalen, 1980)

Paternal investment is minimal. However, males often defend mates, and prior to mating, defend territories that are more likely to attract potential mates. At age 4, male offspring begin following adult males and spend less time with their mothers. (Symington, 1988; van Roosmalen, 1980)

The oldest black spider monkey in captivity lived to be 46 years old, however, few live past 40. The oldest female, which is still being tracked in the wild, is 37.8 years old. In captivity the oldest recorded female lived to be 34 years old. (Allman, et al., 1996; Lindenfors, 2002; de Magalhaes and Costa, 2009)

Black spider monkeys rarely associate with other primate species, but live in large groups of 20 to 30 individuals. During the daytime they split into subgroups while traveling, feeding, and resting. Although subgroup size averages 2.4 individuals, the largest subgroup recorded was 9 individuals. Individual females have their own territories within the groups home-range, and very rarely associate with other females. Feeding and traveling take up 29%±2% and 26%±1% of their daily time budget, respectively, with most of their time spent resting (45%±1%). The majority of travel is conducted in the forest canopy by swinging to and from branches. Black spider monkeys rest two times a day, typically from 08:00 to 10:00 and from 12:00 to 14:30. Due to decreased food availability, rest periods tend to be longer during the dry season. (Mittermeier, et al., 2009; Symington, 1988)

Black spider monkeys have an average home-range of 2.55 km^2. Females with infants generally stay within a “core area” that makes up 20 to 33% of their group’s total home-range. Males spend more time traveling throughout their territory than females, which spend more time feeding. Males defend group territories by being very vocal and aggressive toward potential competitors. (Mittermeier, et al., 2009; Symington, 1988)

Black spider monkeys communicate in many different ways. They recognize and remember past relationships by smelling or licking each others’ chest and genital regions. They vocally communicate with each other by screaming, grunting, whistling, and barking, which warns others of predators and clarifies where food can be found. They visually communicate with each other by scratching their chests, shaking tree branches, throwing objects from trees, nodding their heads, and swinging their arms. (Cheney and Seyfarth, 1990; Mittermeier, et al., 2009; Smock, 2008)

Black spider monkeys gather food in subgroups of no more than 3 individuals, especially during the dry season when less food is available. During the wet season, groups typically consist of two dominant females and up to nine subordinate individuals. Individuals are far more likely to be seen together and interacting during the wet season. During the dry season, a single dominant female leads the group in finding food and is joined by either a non-dominant female or male. Black spider monkeys feed for the first two hours after waking and the last two hours before they go to sleep at night. (Mittermeier, et al., 2009; Symington, 1988; van Roosmalen, 1980)

Black spider monkeys prefer fruit, which is abundant during the wet season (January-April) and makes up about 85.4% of their diet. As a result, they spend over three quarters of their time in the upper canopy searching for fleshy berries, drupes, pods, and compound fruits. They may consume fruit whole (40% of the time) or bite off the outer layer and ingest the interior fruit tissue. They also eat leaves (9.5%), flowers (2.5%), mature seeds (1.8%), and tips of roots and fungi (0.7%). During the dry season (June and July), when fruit is scarce, they ingest a higher percentage of flowers and may consume honey, decaying wood, or tree bark. Although not preferred, they also consume insects such as termites and caterpillars. Preferred tree families are Sapotaceae and Moraceae (produce a milky juice and fleshy fruits), Myristicaceae (produce preferable seeds), and Mimosaceae (woody shrubs and trees). (Mittermeier, et al., 2009; Symington, 1988; van Roosmalen, 1980)

Black spider monkeys are relatively large and are not often preyed upon. However, their predators include jaguars (Panthera onca), pumas (Puma concolor), ocelots (Leopardus pardalis), margay (Leopardus wiedii), and harpy eagles (Harpai harpyja). Humans have also become a major predator of this species, causing more deaths than any of their natural predators. (McFarland, 1986)

Black spider monkeys are important seed dispersers for various tree species. They are also host to parasitic worms (Tetrapetalonema marmosetae) and parasitic protozoa known to cause a specific form of primate malaria (Plasmodium brasilianum). (Chazdon and Whitmore, 2002; Dunn and Lambrecht, 1963a; Dunn and Lambrecht, 1963b; Lehman, 2000)

Black spider monkeys are hunted as game because of their large size and an increasing demand for bushmeat. However, because of their declining population numbers, hunting may be illegal throughout parts of their range in South America. In Bolivia, although not scientifically proven, their fat has been used for many years as a home remedy for rheumatism. They are also commonly found in zoos. (Alves, et al., 2010)

There are no known adverse effects of black spider monkeys on humans.

Black spider monkeys are listed as vulnerable on the IUCN Red List. Currently, populations numbers are declining. Due to deforestation, hunting by humans, and its slow reproductive rate, black spider monkeys are especially susceptible to further decline. (Mittermeier, et al., 2009)