Saimiri oerstedii


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Saimiri oerstedii
Species Authority: (Reinhardt, 1872)
Infra-specific Taxa Assessed:
Common Name/s:
English Black-crowned Central American Squirrel Monkey, Central American Squirrel Monkey, Red-backed Squirrel Monkey
French Saïmiri À Dos Roux, Singe-écureuil À Dos Rouge, Singe-écureuil À Dos Roux
Spanish Barizo Dorsirrojo, Mono Ardilla, Mono Titi, Mono Tití, Titi
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.

See Rylands et al. (2006) for a discussion of the taxonomy of the Central American squirrel monkeys.

Assessment Information [top]

Red List Category & Criteria: Vulnerable B1ab(ii,iii) ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor/s: Wong, G., Cuarón, A.D., Rodriguez-Luna, E. & de Grammont, P.C.
Reviewer/s: Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This species is listed as Vulnerable due to its having an extent of occurrence of ~8,000 km², a severely fragmented range, and because of continued loss of habitat.
2003 Endangered
2003 Endangered (IUCN 2003)
2000 Endangered
1996 Endangered
1994 Endangered (Groombridge 1994)
1990 Endangered (IUCN 1990)
1988 Endangered (IUCN Conservation Monitoring Centre 1988)
1986 Endangered (IUCN Conservation Monitoring Centre 1986)
1982 Endangered (Thornback and Jenkins 1982)

Geographic Range [top]

Range Description:Saimiri oerstedii occurs along the Pacific coast of Costa Rica and Panama inland to altitudes of up to 500 m asl. The north-eastern limit is marked by the Río Tulín in the north Herradura Mountains (9°40’N, 84°35’W) and Dota Mountains (9°37’N, 84°35’W). Along the coast of the Golfo Dulce and the Burica Peninsula to the western part of the Chiriquí Province, mouth of the Río Fonseca, including the Archipelago of the Golfo de Chiriquí, in Panama (Hershkovitz 1984; Boinski et al. 1998; Reid 1997).

There are two subspecies:

Saimiri oerstedii oerstedii occurs along the Pacific coast of Costa Rica, from the left bank of the Río Grande de Térraba to the Osa Pensinsula, along the coast of the Golfo Dulce and the Burica Peninsula to the western part of the Chiriquí Province, mouth of the Río Fonseca, including the Archipelago of the Golfo de Chiriquí, in Panama (Hershkovitz 1984; Boinski et al. 1998; Reid 1997). Surveys by Baldwin and Baldwin (1972, 1976) recorded its presence on the Burica Peninsula, but indicated that it is now restricted to a narrow strip of scattered lowland coastal forest fragments, not extending to the type locality David, although it possibly occurred as far east as Remedios (well to the east of David) prior to the 1950s. Altitudinal range is 0 to 500 m asl (Hershkovitz 1984). Rodríguez-Vargas (2003) mapped the remaining populations in Panama.

The historic range of Saimiri oerstedii citrinellus is along the Pacific coast of Costa Rica, to altitudes of up to 500 m asl. The north-eastern limit is marked by the Río Tulín in the north Herradura Mountains (9°40’N, 84°35’W) and Dota Mountains (9°37’N, 84°35’W), and the southern limit is the north bank of the Río Grande de Térraba (8°25´N, 84°25´W) (Arauz 1993; Sierra et al. 2003). Its occurrence is sporadic, and the surviving populations are entirely fragmented (Alfaro 1987; Wong 1990; Sierra et al. 2003).
Costa Rica (Costa Rica (mainland)); Panama
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population: Mitchell et al. (1991) recorded a population density of 36 individuals/km² in Costa Rica; Baldwin and Baldwin (1981) recorded 130 individuals/km² n Panama.

There is some dispute by different teams as to total numbers of S. o. citrinellus. The larger estimate is 1300-1800 individuals (Wong 1990; Sierra et al. 2003; but see Boinski et al. 1998).
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: Typically prefers seasonally inundated forests, river edge forest, floodplain, and secondary forests (see Boinski 1987c). 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. oerstedii, females do not form dominance hierarchies, and there is no evidence of coalition formation in social interactions. Females transfer between groups before first mating season, and males are philopatric. There is little competition or agonistic interactions between groups, and males show high levels of vigilance for predators. Reproductively mature males collaborate in mobbing females during the mating season. Their fruits they typically exploit occur in small and very scarce patches, and feeding competition is very low.

Mating and births in Saimiri are highly seasonal, seldom exceeding two months in duration (see Boinski 1987a,b). Single offspring, qwith interbirth intervals of about 12 months (Boinski 1999b). Mating usually occurs during the dry season. In S. oerstedii, sexual receptivity in females is synchronized, and lasts only one or two days each season. In S. sciureus, birth synchrony is less pronounced and births occur only once every two years.

Weight: Adult male 750-950 g (mean 829 g), adult female more than 600-800 g (mean 695 g) (Jack 2007).
Systems: Terrestrial

Threats [top]

Major Threat(s): The major threat to this species across its range is habitat loss, primarily due to agriculture and logging.

Conservation Actions [top]

Conservation Actions: This species is listed on CITES Appendix I. It occurs, or may occur, in numerous protected areas:

Saimiri oerstedii oerstedii Costa Rica, Panama

Costa Rica
Corcovado National Park (41,789 ha) (Boinski and Sirot 1997; Matamoros et al. 1996; Matamoros and Seal 2001)
Golfito National Park of (2,830 ha) (Matamoros et al. 1996; Matamoros and Seal 2001)
Piedras Blancas National Park (14,100 ha) (within range)
Portalón National Wildlife Refuge (within range)
Preciosa Platanares National Wildlife Refuge (within range)
Punta Río Claro National Wildlife Refuge (within range)
Pancho La Merced National Wildlife Refuge (within range) )
RHR Bancas National Wildlife Refuge (within range)
Transilvania National Wildlife Refuge (within range)
Donald Peter Hayes National Wildlife Refuge (within range)
Finca Barú del Pacífico National Wildlife Refuge
Forestal Golfito SA National Wildlife Refuge
Hacienda Copano National Wildlife Refuge
Lacustrino Pejepperrito Protection Zone (0.7 ha) (within range)
Pejeperro Protection Zone (500 ha) (within range) (within range)
Golfo Dulce Forest Reserve (70,000 ha) (Boinski and Sirot 1997)
Sierpe Térraba Forest Reserve (32,960 ha) (within range)
Los Santos Forest Reserve (62,000 ha) (within range)
Osa Anthropological Reserve (1,700 ha) (Matamoros and Seal 2001)
Térraba Anthropological Reserve (9,350 ha) (within range)
Conte Burica Anthropological Reserve (11,910 ha) (Matamoros and Seal 2001).

El Chorogo - Palo Blanco Wildife Refuge (proposed, within range).
Cerre Cerrezuela – Rio Grande (within range)
Playa de la Barqueta Agricola (possible occurrence: Matamoros and Seal 2001)
Estero Golfo de Montijo Recreation Area (89,452 ha) (within range)
Golfo de Chiriquí National Park (14,740 ha) (Matamoros and Seal 2001).

Saimiri oerstedii citrinellus

Costa Rica
Manuel Antonio National Park (683 ha) (Boinski and Sirot 1996; Matamoros et al. 1996; Matomoros and Seal 2001)
Carara Biological Reserve (4,700 ha) (Rodríguez-Luna et al. 1996a,b; just to north of known range, not confirmed) - this subspecies has not been seen in this protected area
Cerro de Turrubares Protection Zone (2,340 ha) (Rodrigues-Luna et al. 1996; within historic range, not confirmed).

Bibliography [top]

Alfaro, A. 1897. Mamíferos de Costa Rica. Tipografía Nacional, San José, Costa Rica.

Arauz, J. 1993. Estado de Conservación del Mono Tití (Saimiri oerstedi citrinellus) en su Area de Distribución Original, Manuel Antonio, Costa Rica. M.Sc. Thesis, Universidad Nacional Autonoma (UNA).

Baldwin, J. D. and Baldwin, J. I. 1972. The ecology and behavior of squirrel monkeys (Saimiri oerstedi) in a natural forest in western Panama. Folia Primatologica 18: 161-184.

Baldwin, J. D. and Baldwin, J. I. 1976. Primate populations in Chiriquí, Panama. In: R. W. Thorington, Jr. and P. G. Heltne (eds), Neotropical Primates: Field Studies and Conservation, pp. 20-31. National Academy of Sciences, Washington, DC.

Baldwin, J. D. and Baldwin, J. I. 1981. The squirrel monkeys, genus Saimiri. In: A. F. Coimbra-Filho and R. A. Mittermeier (eds), The Ecology and Behavior of Neotropical Primates, pp. 277-330. Academia Brasileira de Ciências, Rio de Janiero, Brazil.

Boinski, S. 1987. Birth synchrony in squirrel monkeys (Saimiri oerstedii): a strategy to reduce neonatal predation. Behavioral Ecology and Sociobiology 21: 393-400.

Boinski, S. 1987. Habitat use by squirrel monkeys (Saimiri oerstedii) in Costa Rica. Folia Primatologica 49: 151-167.

Boinski, S. 1987. Mating patterns in squirrel monkeys (Saimiri oerstedii): implications for seasonal sexual dimorphism. Behavioral Ecology and Sociobiology 21: 13-21.

Boinski, S. 1988. Sex differences in the foraging behavior of squirrel monkeys in a seasonal habitat. Behavioural Ecology and Sociobiology 23: 177-186.

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Boinski, S., Ehmke, E., Kauffman, L., Schet, S. and Vreedzaam, A. 2005. Dispersal patterns among three species of squirrel monkeys (Saimiri oerstedii, S. boliviensis and S. sciureus): II. Within-species and local variation. Behaviour 142(5): 633-677.

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Matamoros, Y. and Seal, U. S. 2001. Informe Final. Taller para la Conservación Asesoramiento y Manejo Planificado para los Primates Mesoamericanos, Parque Zoológico Simón Bolívar, San José, Costa Rica, 23-25 Junio 1997. IUCN/SSCConservation Breeding Specialist Group (CBSG), Apple Valley, Minnesota, USA.

Matamoros,Y., Wong, G. and Seal, U. S. 1996. Taller de Evaluación de Viabilidad de Población y Hábitat de Saimiri oerstedi citrinellus. IUCN/SSCConservation Breeding Specialist Group (CBSG), Apple Valley, Minnesota, USA.

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Rodríguez-Vargas, A. R. 2003. Analysis of the hypothetical population structure of the squirrel monkey (Saimiri oerstedii) in Panamá. In: L. K. Marsh (ed.), Primates in Fragments: Ecology and Conservation, pp. 53-62. Kluwer Academic / Plenum Publishers, New York, USA.

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Wong, G. 1990. Uso del hábitat, estimación de la composición y densidad poblacional del mono tití (Saimiri oerstedi citrinellus) en la zona de Manuel Antonio, Quepos, Costa Rica. M.Sc. Thesis, Universidad Nacional Autonoma (UNA).

Citation: Wong, G., Cuarón, A.D., Rodriguez-Luna, E. & de Grammont, P.C. 2008. Saimiri oerstedii. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 19 April 2014.
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