Ateles fusciceps


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Ateles fusciceps
Species Authority: Gray, 1866
Infra-specific Taxa Assessed:
Common Name(s):
English Brown-headed Spider Monkey, Black-headed Spider Monkey
Taxonomic Notes: The taxonomy of the spider monkeys is based on Kellogg and Goldman (1944) and Hill (1962). The forms hybridus, chamek and marginatus are listed as distinct species and A. fusciceps robustus Allen, 1914 is considered a junior synonym of A. f. rufiventris Sclater, 1871 following Heltne and Kunkel (1975) (see Rylands et al. 2000). Silva-López et al. (1996) argued that Ateles geoffroyi pan was not a valid taxon. Hernández-Camacho and Defler (1989) and Defler (2004) argued for the validity of the form brunneus Gray, 1872, listed here as a subspecies of A. hybridus.

Collins and Dubach (2000) argued that the forms fusciceps and rufiventris are subspecies of Ateles geoffroyi. The taxonomy and distributions of Ateles geoffroyi and Ateles fusciceps are reviewed by Rylands et al. (2006).

Ateles f. rufiventris Sclater, 1871, from the Río Atrato, Darien, Colombia, is listed as incertae sedis by Kellogg and Goldman (1944). Heltne and Kunkel (1975) argued that A. fusciceps robustus Allen, 1914 is a junior synonym ofA. f. rufiventris Sclater, 1871. Medeiroset al. (1997) indicated that, from the cytogenetic viewpoint, rufiventris Sclater, 1871, may well be reproductively isolated from A. geoffroyi.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2cd ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Cuarón, A.D., Shedden, A., Rodríguez-Luna, E., de Grammont, P.C. & Link, A.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This species is listed as Critically Endangered due to an estimated population decline of more than 80% over the past 45 years (three generations) due to severe habitat loss and hunting pressure throughout its range.

Geographic Range [top]

Range Description: There are two recognized subspecies:

Ateles fusciceps fusciceps is endemic to Ecuador, in the north, west of the Andes, in the Province of Esmeraldas, and, at least historically it would seem, south as far the Cordillera de Colonche (Tirira 2007). There are two populations remaining: one in the Chongon Colonche Mountain Range and the another in the Cotacachi-Cayapas Reserve and surrounding forests in the north. Hernández-Camacho and Cooper (1976) suggested that A. f. fusciceps might occur in southern Colombia, south of the Río Mira, continuous with the populations in Ecuador, but no evidence has been forthcoming regarding this.

Ateles fusciceps rufiventris ranges from the western cordillera of the Andes from south-western Colombia, northward on west side of the Río Cauca to eastern Panama (Cerro Pirre and the basin of the Río Bayano of the Pacific coast) (Rylands et al. 2006). The Cerro Pirre or the Río Tucutí mark the border with A. geoffroyi grisescens. In Colombia, A. f. rufiventris occurs throughout the Pacific lowlands except for Juradó, norh-western part of the Department of Chocó, supposedly the domain of A. g. grisescens (Hernández-Camacho and Cooper 1976; Defler, 2003, 2004). It occurs in the Urabá region in north-western Antioquia, Córdoba, Sucre, and northern Bolívar east to the lower Río Cauca along the western bank to south-central Antioquia. The most southerly record in Colombia is Barabacoas, Department of Nariño, and the most northerly is southern bank of the Canal del Dique, Cartagena. Hernández-Camacho and Cooper (1976) believed that it formerly occurred as far north as Pendales.

Ateles f. rufiventris does not occur in Ecuador and is discontinuous with A. f. fusciceps. Furthermore, this subspecies range in Colombia is likely fragmented in the southern part of its range. There are only two known locations in the Chocó region.
Colombia (Colombia (mainland)); Ecuador (Ecuador (mainland)); Panama
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Ateles fusciceps fusciceps is rare and diifficult to see (Madden and Albuja 1989). In Cotacachi-Cayapas, this subspecies is found in population densities of 1.2 individuals/km² (Gavilanes and Endara 2006).

There is no population information available for Ateles fusciceps rufiventris.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: In Ecuador (A. f. fusciceps), tropical and subtropical humid forests from 100 to 1,700 m above sea level (Tirira 2007). In Colombia (A. f. rufiventris), Hernández-Camacho and Cooper (1976) recorded that it occurs in dry forest, humid forest and cloud forest, occupying the greatest range of forest habitats of any of the Colombian spider monkeys. Defler (2004) indicated that they range as high as 2,000-2,500 m above sea level in the Cordilllera Occidental.

Spider monkeys travel and forage in the upper levels of the forest. They spend much time in the canopy and also use the middle and lower strata but are rarely seen in the understorey. In accordance with their use of the highest levels of the forest, they are highly suspensory. When travelling they spend more time hanging from branches, moving by brachiation and arm swinging, and climbing than they do walking or running on all fours. They are highly frugivorous and feed largely on the mature, soft parts of a very wide variety of fruits, which comprise 83% of their diet and are found mainly in the emergent trees and upper part of the forest canopy (Van Roosmalen and Klein 1988). They also eat young leaves and flowers (both especially at times of fruit shortage during the beginning of the dry season), and besides such as young seeds, floral buds, pseudobulbs, aerial roots, bark, decaying wood, and honey, and very occasionally small insects such as termites and caterpillars. They play a significant role as seed dispersers. Van Roosmalen (1985; Van Roosmalen and Klein 1988) found that A. paniscus was dispersing the seeds of at least 138 species (93.5% of all fruits species used) through their ingestion and subsequent defecation (endozoochory). A further 10 species were being dispersed by the monkeys carrying them off some distance from the tree before dropping them (exozoochory). In only 23 species were the seeds being ruined or eaten (seed predation).

Spider monkeys live in groups of up to 20-30 individuals (for review see Van Roosmalen and Klein 1988). However, they are very rarely all seen together, and nearly always to be found travelling, feeding and resting small in groups of varying size and composition (most usually 2-4), the only persistent association being that of a mother and her offspring (McFarland Symington 1990). Group members will also travel on their own. Each female in the group has a “core area” of the group’s home range which she uses most. Klein and Klein (1976, 1977) estimated 259-388 ha ranges with 20-30% overlap for A. belzebuth in La Macarena National Park, Colombia. Ateles are rarely seen in association with other primates and mostly they are occasional and ephemeral, resulting from the simultaneous occupation of fruiting trees.

Six estimated birth dates given by Klein (1971) for A. belzebuth, were spread throughout the year (December, January, April, September, October and November). Spider monkeys apparently reach sexual maturity at 4-5 years of age (Klein 1971; Eisenberg 1973, 1976). They give birth to single offspring after a long gestation period of 226-232 days, with a minimum theoretical interbirth interval in captivity of 17.5 months, but in the wild probably as long as 28-30 months (Eisenberg 1973, 1976). Late maturation and long inter-birth intervals make it difficult for them to recover from hunting and other threats.
Systems: Terrestrial

Threats [top]

Major Threat(s): Ateles fusciceps fusciceps
Tirira (2001) has reported an 80% reduction in population size based on habitat loss. This species has a very small distribution, is highly fragmented, and is under pressure from a high rate of habitat loss due to deforestation and strong hunting pressure.

Ateles fusciceps rufiventris
In Colombia, Defler et al. (2003) all spider monkeys are considered threatened due to hunting and habitat loss and fragmentation. National Parks such as Katios and Orquideas are believed to have very few spider monkeys because of indigenous hunting pressure (N. Vargas pers. comm.; H. Rubio pers. comm.) and the population density of Ateles may be decreasing in Los Katios (Director del Parque Los Katios, D. Pintor pers. comm.). Widespread censuses of Ateles are needed, especially in national parks.

In Colombia, along the Atlantic coast, it has been estimated that over 30% of habitat has been lost in the past 10 years based on calculations from satellite photos (Miller et al, 2004). Ground truthing of this data found only 2.5% of viable secondary forest habitat was left in this region (Miller et al. 2004). In Panama, there is a lower human population and likely higher habitat availability, but more research is needed to determine population status and threats to this subspecies.

Conservation Actions [top]

Conservation Actions: In Ecuador, Ateles fusciceps fusciceps is protected in accordance with Resolution No. 105 of the Ministry of the Environment (Registro Oficial No. 5 of 28 January 2000) (Tirira 2001). This prohibits hunting and commercialization throughout Ecuador.

Tirira (2001) proposes the following measures:
Research on its range and the size and status of remaining populations;
Evaluation of the effectivness of the protected areas where it occurs;
Research on its ability to cope with deforestation and forest fragmentation, and proximity to humans and their activities;
Research on the extent of illegal hunting by colonists and Indigenous people;
Evaluate the needs and possibilities for increasing the size of the current protected areas and providing for more protected areas where it occurs;
Carry out education awareness campaigns and environmental education programs in its range - emphasizing particularly aspects of the traffic in, and commercialization of, primates; and
Ex situ breeding programme, and associated research needed for such (e.g., husbandry, reproduction) .

The subspecies are recorded from the following protected areas:

Ateles fusciceps fusciceps

Cotacachi-Cayapas Ecological Reserve (243,638 ha) (Tirira 2007)
Los Cedros Protected Forest (Tirira 2007)
Awá Ethnological Reserve (Tirira 2007)

Ateles fusciceps rufiventris

Los Katios Natural National Park (72,000 ha)
Las Orquideas Natural National Park (32,000 ha)

It is listed on Appendix II of CITES.

Citation: Cuarón, A.D., Shedden, A., Rodríguez-Luna, E., de Grammont, P.C. & Link, A. 2008. Ateles fusciceps. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 19 December 2014.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided