Saimiri sciureus


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Saimiri sciureus
Species Authority: (Linnaeus, 1758)
Infra-specific Taxa Assessed:
Common Name/s:
English Common Squirrel Monkey, South American Squirrel Monkey
Spanish Macaco-de-cheiro
Taxonomic Notes: Saimiri taxonomy follows Hershkovitz (1984) and Groves (2001, 2005). An alternative taxonomy is presented by Thorington Jr. (1985) as follows: S. sciureus sciureus (includes the forms albigena, macrodon, and ustus recognized by Hershkovitz, [1984]), S. sciureus boliviensis (includes the forms pluvialis Lönnberg, 1940 and jaburuensis Lönnberg, 1940 recognized by Hershkovitz [1987]), S. sciureus cassiquiarensis, S. sciureus oerstedii (includes the form citrinellus recognized by Hershkovitz [1984]), and S. madeirae (given as a junior synonym of S. ustus by Hershkovitz [1984]). Hernández-Camacho and Defler (1989) recognize S. sciureus caquetensis Allen 1916, given as a junior synonym of S. sciureus macrodon by Hershkovitz (1984). Costello et al. (1993) argued for the recognition of just two species: S. sciureus in South America, and S. oerstedii in Panama and Costa Rica. Boinski and Cropp (1999) using two nuclear genes (IRBP and ZFX) and one mitochondrial (D-Loop) strongly support the Hershkovitz (1984) taxonomy, advocating four distinct species: Saimiri sciureus, S. boliviensis, S. oerstedii and S. ustus.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor/s: Boubli, J.-P., Rylands, A.B., de la Torre, S. & Stevenson, P.
Reviewer/s: Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This species is listed as Least Concern, given its relatively wide range, adaptability to some degree of disturbed forest, and apparent lack of major threats. Additionally, given its small size, it is not generally hunted. However, populations undoubtedly are declining in some areas due to forest destruction and fragmentation.
2003 Least Concern (IUCN 2003)
2003 Least Concern

Geographic Range [top]

Range Description: There are four recognized subspecies:

Saimiri sciureus sciureus is a wide-ranging subspecies in the north-eastern and eastern Amazon. Distribution, according to Hershkovitz (1984), extends through the Guianas, Amapá and the Brazilian Amazon east of the Rios Deminí and Negro north of the Rio Amazonas, and east of the Rio Xingú south of the Rio Amazonas, Guyana. Silva Jr. (unpublished) places it east of the rios Tapajós and Juruena to extending east to upper reaches of the Rio Teles Pires, a little north and then east, south of the Serra od Cahimobo, across the middle Xingu, the Araguaia and Tocantins to the Rio Parnaiba valley in Maranhão. Hershkovitz (1984) placed its eastern limit as the Rio Pindaré in Maranhão. It also occupies a small area south of the Rio Solimões between the Rio Madeira and the Tapajós on the Ilha Tupinambarama, east to Parintins. Saimiri s. sciureus has not been recorded above 100 m above sea level.

The range of Saimiri sciureus albigena according to Hershkovitz (1984) is gallery forests of the Colombian llanos (Llanos Orientales) from the eastern slope of the Cordillera Oriental in the Departments of Arauca, Casanare and Guaviare, and the departments of Boyacá, Cundinamarca, and Meta to unknown limits eastward. It also occurs in the upper Río Magdalena, but how far it extends north in the Magdalena valley is not known (Hernández-Camacho and Cooper 1976; Defler 2003; 2004). Altitudinal range between 150 and 600 m or higher, possibly to 1,000 m.

The range of Saimiri sciureus cassiquiarensis according to Hershkovitz (1984) is the upper Amazon and Orinocean regions, in Brazil the state of Amazonas from north of the Rio Solimões and west of the Rios Demini and Negro into the Orinoco-Cassiquiare basin in Venezuela, form there west into eastern Colombia between the Ríos Apaporis and Inírida in the Departments of Vaupés, Guaviare and Guiania (Hernández-Camacho and Cooper 1976; Defler 2003; 2004). Occurrence in Venezuela was mapped by Bodini and Pérez-Hernández (1987) and Linares (1998).

Saimiri sciureus macrodon, according to Hershkovitz (1984), ranges in upper Amazon, in Brazil in the state of Amazonas between the Rios Juruá and Japurá, westward; in Colombia from the Rio Apaporis south into eastern Ecuador, throughout the Ecuadorian Amazon east pf the Andes to asltitidues of 1,200 m (Tirira 2007), and into Peru in the departments of San Martín and in Loreto, to the north bank of the Río Marañon-Amazonas. Hershkovitz (1984) indicated that the portion of the range between the Ríos Ucayali and Tapiche is occupied by both S. s. macrodon and S. boliviensis peruviensis (see also Aquino and Encarnación 1994). In Peru, it extends south as far as the ríos Amazonas and Marañón and west of the Huallaga to the Andes, south to a little beyond 8ºS. It extends south of the Rio Amazonas east of the Río Ucayali from the Rio Blanco, where it is sympatric with Saimiri boliviensis peruviensis (Aquino and Encarnación 1994). East of the Ucayali it ranges south to the west of the Serra do Divisor, but not known to reach the Río Tamaya.
Brazil (Amapá, Amazonas, Maranhão, Mato Grosso, Pará, Roraima, Tocantins); Colombia (Colombia (mainland)); Ecuador (Ecuador (mainland)); French Guiana; Guyana; Suriname; Venezuela, Bolivarian Republic of (Venezuela (mainland))
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Recorded population densities for S. s. macrodon include:

Klein and Klein (1975) recorded a density of 50-80 individuals/km² at La Macarena, Colombia;
Peres (1997) estimated population densities at the following várzea (white-water flooded forest) sites: Nova Empresa 73.8 individuals/km²; Barro Vermelho II 109.5 individuals/km²; Lago da Fortuna 189.8 individuals/km². They are more scarce in terra firma forests: Sobral 5.9 individuals/km²; Condor 36.1 individuals/km²; Barro Vermelho I 16.7 individuals/km²; Fortuna 23.2 individuals/km²; Vira Volta 17.7 individuals/km²; Riozinho 36.4 individuals/km².
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Saimiri sciureus typically prefers seasonally inundated forests, river edge forest, floodplain, and secondary forests. Can also be found in gallery forest, low forests of sclerophytic vegetation, forested slopes, and palm forests (particularly associations of Mauritia flexuosa). They use all levels of the forest, but forage and travel mainly in the lower canopy and understorey. Locomotion involves predominantly quadupredal walking and running.

Squirrel monkeys are small frugivore-insectivores. They spend 75-80% of their day foraging for insects and other small animal prey (Mittermeier and Van Roosmalen 1981; Terborgh 1983; Boinski 1988). During dry season shortages of appropriate fruiting trees they are able to depend entirely on animal prey (Janson and Boinski 1992).

Saimiri groups are multi-male and can be large, up to 100 animals (larger groups are believed to be temporary mergers of two) but most frequently are of 20-75 individuals (Baldwin and Baldwin 1981; Terborgh 1983; Mitchell et al. 1991). As emphasized by Boinski (1999a,b; 2005; Boinski et al. 2005a,b), allthough all squirrel monkeys are morphologicallly very similar, their social systems are quite distinct (summarized in Sussman 2000).

In S. sciureus, studied in Suriname by Boinski (1999a,b, 2005; Boinski et al. 2005a,b), group sizes range from 15 to 50, and both sexes form a single, linear hiearchy in the group, with most males being dominant to females. Aggression between females is uncommon, but they do not form coalitions. Males form coalitions and can aggressive to each other. Males show vigilance in defense agianst predators. The fruits they exploit typically occur in small but extremely dense patches, and there is considerable feeding competition between group members, much higher than in S. boliviensis.

Mating and births in Saimiri are highly seasonal, seldom exceeding two months in duration. Single offspring. Mating usually occurs during the dry season. In S. sciureus, birth synchrony is less pronounced and births occur only once every two years.

Saimiri boliviensis and S. sciureus frequently form interspecific associations, travelling with Cebus albifrons or Cebus apella (Terborgh 1983; Wallace et al. 2000), benefitting from the disturbance casued by the capuchin monkeys above them which flushes out insects.

Weight: Adult male 740 g, adult female more than 635 g (Jack 2007).
Systems: Terrestrial

Threats [top]

Major Threat(s): Saimiri sciureus is wide-ranging throughout the northern Amazon. The species occupies secondary forest and is often found close to human settlements. Although they are not commonly hunted because of their small size, in some parts of their range, such as Colombia and Ecuador, they are commonly trapped for the pet market (Defler 2003, 2004; S. de la Torre pers. comm.).

In Colombia, Saimiri sciureus albigena occurs in a region subject to high rates of deforestation.

Conservation Actions [top]

Conservation Actions: This species is listed on CITES Appendix II. It occurs, or may occur, in a number of protected areas:

Saimiri sciureus sciureus

Tumucumaque National Park (3,882,376 ha)
Cabo Orange National Park (630,017 ha)
Gurupí Biological Reserve (272,379 ha)
Lago Piratuba Biological Reserve (394,223 ha)
Rio Trombetas Biological Reserve (409,578 ha)
Uatumã Biological Reserve (942,786 ha)
Jari Ecolopical Station (207,370 ha)
Terra do Meio Ecological Station (3,373,111 ha)
Niquia Ecological Station (282,803 ha)

French Guiana
Parc amazonien de Guyane (3,300,000 ha)
Nouragues Natural Reserve (100,000 ha) (Kessler 1998)

Kaieteur Narional Park

Brinckheuvel Nature Reserve (6,000 ha) (probable: Mittermeier and van Roosmalen 1982)
Central Suriname Nature Reserve (1,600,000 ha) (Mittermeier and van Roosmalen 1982)
Coppename Monding Nature Reserve (12,000 ha) (unconfirmed (Mittermeier and van Roosmalen 1982)
Sipaliwini Nature Reserve (100,000 ha) (Mittermeier and van Roosmalen 1982)
Brownsberg Nature Park (8,400 ha) (Mittermeier and van Roosmalen 1982)

Saimiri sciureus albigena

Cordillera de los Picachos Natural National Park (286,600 ha) (in range)
El Cocuy Natural National Park (306,000 ha) (in range?)
Serranía de la Macarena Natural National Park (630,000 ha) (in range) (or cassiquiarensis?)
Tinigua Natural National Park (201,875 ha) (in range)? (or cassiquiarensis?)

Saimiri sciureus cassiquiarensis

Pico da Neblina National Park (2,298,154 ha)
Jau National Park (2,378,410 ha)
Juamí Japurá Ecological Station (832,078 ha)

Nukak Natural National Reserve (855,000 ha) (in range)
Puinawai Natural National Reserve (1,092,500 ha) (in range)

Saimiri sciureus macrodon

Amacayacu Natural National Park (293,000 ha) (in range)
Cahuinarí Natural National Park (575,500 ha) (in range)
Serrania de Chiribiquete Natural National Park (1,280,000 ha) (in range)
Cueva de los Guacharos Natural National Park (9,000 ha) (in range)
La Paya Natural National Park (442,000 ha (in range, Polanco-Ochoa et al. 1999)

Yasuní National Park (Tirira 2007)
Cayambe-Coca Ecological Reserve (Tirira 2007)
Cofán-Bermejo Ecological Reserve (Tirira (2007)
Cuyabeno Faunal Protection Reserve (Tirira 2007)

Tamshiyacu-Tahuayo Communal Reserve (Aquino and Encanrfación 1994)
Citation: Boubli, J.-P., Rylands, A.B., de la Torre, S. & Stevenson, P. 2008. Saimiri sciureus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 20 April 2014.
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