Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Aotidae

Scientific Name: Aotus griseimembra
Species Authority: Elliot, 1912
Common Name(s):
English Grey-handed Night Monkey, Grey-legged Night Monkey
Spanish Mico De Noche Caribeño
Taxonomic Notes: It is doubtful that the current taxonomy provides a true picture of the diversity of the genus Aotus. Ruiz-Herrera et al. (2005) reported that cytogenetic studies have characterized 18 different karyotypes with diploid numbers ranging from 46 to 58 chromosomes. The taxonomy of the night monkeys essentially follows the revision by Hershkovitz (1983), with some modifications for the Colombian and Central American forms.

Reviewing the entire taxonomy and distributions of the night monkeys, Aotus, Ford (1994) carried out multivariate analyses of craniodental measures and pelage patterns and color, and also took into consideration chromosomal data and blood protein variations. Ford (1994) concluded that there was “good support” for just two species north of the Río Amazonas: A. trivirgatus (Humboldt, 1812) east and north of the Rio Negro, and the polymorphic A. vociferans to the west of the Rio Negro. Aotus vociferans, as such, would include all the forms north of the Río Amazonas/Solimões in Brazil (west of the Rio Negro), Peru, Colombia and Ecuador, and in the Chocó, northern Colombia and Colombian Andes, and Panama: brumbacki, lemurinus, griseimembra, and zonalis.

Hernández-Camacho and Cooper (1976) restricted both lemurinus (Colombian Andes, elevations from 1,000 to 1500 m up to 3,000–3,200 m) and griseimembra (northern lowlands, Santa Marta mountains, west to Río Sinú, Río San Jorge, lower Río Cauca and lowlands of middle and upper Río Magdalena) to Colombia, while recognizing the form zonalis as the night monkey of north-western Colombia (Chocó) and Panama. Hershkovitz (1983) recognized lemurinus and griseimembra as distinct, but considered them to be subspecies of a single species; he made no mention of the name zonalis, but as he ascribed Central American night monkeys to A. lemurinus lemurinus, by implication he was regarding it as a synonym of this latter form. Groves (2001) followed Hernández-Camacho and Cooper (1976) in recognizing zonalis as the form in Panama, and listed it as a subspecies of lemurinus along with griseimembra and brumbacki Hershkovitz, 1983. Defler et al. (2001) concluded that the karyotype of Aotus hershkovitzi Ramirez-Cerquera, 1983 (from the upper Río Cusiana, Boyacá, Colombia; 2n = 58) was in fact that of true lemurinus, and that the karyotypes which Hershkovitz (1983) had considered to be those of lemurinus were in fact of zonalis. Defler et al. (2001) and others (Defler 2003, 2004; Defler and Bueno 2003) concluded that Aotus lemurinus of Hershkovitz (1983) is in fact three karyotypically well-defined species, and that the night monkeys of the lowlands of Panama and the Chocó region of Colombia belong to the species A. zonalis, and those of the Magdalena valley to A. griseimembra, while those above altitudes of 1500m should correctly be referred to as A. lemurinus. For a review of the taxonomy of the night monkeys of Panama and northern Colombia see Rylands et al. (2006).

Defler and Bueno (2007) discussed the karyology of the grey-necked night monkeys and reaffirmed the validity of A. brumbacki, A. griseimembra, A. lemurinus, A. trivirgatus, A. vociferans and A. zonalis.

Assessment Information [top]

Red List Category & Criteria: Vulnerable A2c ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Morales-Jiménez, A.L. & Link, A.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This species is listed as Vulnerable based on the rate of loss of habitat across its range and an inferred population decline at a rate greater than 30% over the past 3 generations (24 years). As forest loss continues this species should be closely monitored.
Previously published Red List assessments:
2000 Endangered (EN)
1996 Endangered (EN)
1994 Vulnerable (V)

Geographic Range [top]

Range Description: Aotus griseimembra is the night monkey of the Río Magdelena and the valleys of the ríos Cauca and São Jorge in northern Colombia (Hernandez-Camacho and Cooper 1976; Defler 2003, 2004). It extends north to the Sierra Nevada de Santa Marta, partly up the Guajira Peninsula and east across the Sierra de Perija to Lake Maracaibo in Venezuela (Hernandez-Camacho and Cooper 1976; Bodini and Pérez-Hernández 1987; Linhares 1998; Defler 2003, 2004).
Countries occurrence:
Colombia (Colombia (mainland)); Venezuela, Bolivarian Republic of (Venezuela (mainland))
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: No information available. Aquino and Encarnación (1994b) reviewed population structure and densities for the genus.
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: night monkeys typically occur in primary and secondary forest (including disturbed forest and selectively logged forest), seasonally flooded and terra firma, lowland forest, and submontane and montane (cloud forests) in Colombia and the Andes to 3,200 m above sea level (the specifically montane forms are Aotus lemurinus and Aotus miconax) (Hernández Camacho and Cooper 1976; Aquino and Encarnación 1994a; Defler 2004). Aquino and Encarnación (1994b) reviewed the habitat and forest preferences of the genus.

Night monkeys are nocturnal: they are most active at dawn and dusk. The only exception is Aotus azarae azarae of the Chaco of southern Bolivia, Paraguay and Argentina, which is cathemeral (active during night and day). They are frugivorous; their diet includes fruit, nectar and flower (seasonally important for the A. a. azarae in the Chaco) , leaves, and small animals prey such as insects (Wright 1989; Fernandez-Duque 2007). Aotus azarae has been observed to include a significant portion of leaves in its diet (Ganzhorn and Wright 1994; Wright 1985; Arditi and Placci 1990; Giménez and Fernandez-Duque 2003), as has Aotus zonalis on Barro Colorado Island in an early study by Hladik and Hladik (1969).

They are socially monogamous, living in small groups of an adult pair and offspring of different ages (infant, one or two juveniles and sometimes a subadult. In A. a. azarae a significant number of adults range alone. They may be subadults that have left their natal groups or older adults which have been evicted from their groups by competitors (Fernandez-Duque and Huntington 2002; Fernandez-Duque 2004). Both sexes disperse. Males care for the infants (carry them) (Rotundo et al. 2002, 2005). Lone adults were observed by Villavicencio Galindo (2003) in northern Colombia. Night monkeys are territorial—groups occupy overlapping territories of 5-18 ha (depending on the species and location) (Wright 1978; Fernandez-Duque 2007). Wright (1994) and Fernandez-Duque (2007) review the behaviour and ecology of the genus.

Captive male A. lemurinus reach sexual maturity when 2 years old, and captive female A. vociferans and A. nancymaae first breed when 3-4 years old (Dixson 1983; Fernandez-Duque 2007). In the wild, male A. azarae reach adult weight only when about 4 years old, and age at first reproduction is about 5 years of age (Juárez et al. 2003; Fernandez-Duque 2004). A female A. azaraewas found to breed for the first time at 58 months of age (Fernandez-Duque et al. 2002). Single offspring are the rule. Wright (1985) recorded births between August and February for A. nigriceps in Peru (Manu National Park), and Aquino et al. (1990) indicated a birth season between December and March) for A. nancymaae in north-eastern Peru. In the Argentinean Chaco, A. azarae shows a peak of births between March and June (Fernandez-Duque 2007).

Adult male weight average 1.0±0.2 kg (n=20), adult female weight 0.923±0.063 kg (n=16) (Dixson 1983)
Systems: Terrestrial

Threats [top]

Major Threat(s): This night monkey is evidently highly threatened in Colombia, in part due to habitat loss but also because of its capture in the late 1960s and 1970s as an important model for malaria research. Barranquilla was a major port for this commerce. Censuses carried out by Struhsaker et al. (1976) found it to be very scarce, while Green (1978) identified populations in the Sierra San Lucas. This area remains unprotected and could easily be destroyed should the local problems of civil unrest be solved, allowing for colonization.

Conservation Actions [top]

Conservation Actions: This species is confirmed, or may occur, in several protected areas:

Sierra Nevada de Santa Marta National Park (383,000 ha) (in range Defler 2003, 2004)
Iguaque Fauna and Flora Sanctuary (6,750 ha) (Colombia, INDERENA, 1989; Defler 2003, 2004)
Tayrona Natural National Park (15,000 ha) (in range Defler 2003, 2004)
Catatumbo-Barí Natural National Reserve (158,125 ha) (in range Defler 2003, 2004)
Ciénaga Grande de Santa Marta Fauna and Flora Sanctuary (23,000 ha) (in range Defler 2003, 2004)

It is listed on CITES Appendix II.

Citation: Morales-Jiménez, A.L. & Link, A. 2008. Aotus griseimembra. The IUCN Red List of Threatened Species 2008: e.T1807A7650460. . Downloaded on 07 October 2015.
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