|Scientific Name:||Aotus trivirgatus (Humboldt, 1812)|
|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.
The karyotype of Aotus trivirgatus is not known (Defler and Bueno 2007), and Hershkovitz (1983), who based his taxonomy primarily on karyotypes, indicated that further research may result in a revision of this and the forms he recognizes as miconax and infulatus.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Veiga, L.M. & Rylands, A.B.|
|Reviewer(s):||Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)|
This species is listed as Least Concern due to its wide range, presumed large populations, and because there are no major threats believed to be resulting in a significant population decline at present.
|Previously published Red List assessments:|
|Range Description:||Based on a specimen collected at Maipures, near the mouth of the Río Tomo on the Río Orinoco, Defler and Bueno (2007) indicated that the night monkeys of eastern central Colombia north of the Río Guaviare are probably A. brumbacki.|
Hershkovitz (1983) proposed that A. trivirgatus was the form in Colombia between the Rios Vaupés and Inirida, but Defler (2003, 2004) indicated that A. vociferans occurred in this region and that A. trivirgatus as such is restricted to the east of the Ríos Negro, lower Guainia, and Atabapo and, below the mouth the Río Atabapo, the Río Orinoco. To the north, in Venezuela, A. trivirgatus occurs south of the Río Orinoco and east as far the middle Rio Caroni. The extension east beyond the Río Caura is based on just one locality on the upper Caroni (Bodini and Pérez-Hernandez 1987; Linares 1998). A. trivrigatus is confined to north (left bank) of the Rio Negro to its mouth, extending east, north of the Rio Amazonas, as far as the Rio Trombetas. North it reaches the Serra da Pacaraima, but does not it seem extend into Guyana. In the state of Roraima, the Rio Mucajaí is indicated (by Hershkovitz (1983) as marking its northern limits.
Native:Brazil (Amazonas, Pará, Rondônia); Venezuela, Bolivarian Republic of (Venezuela (mainland))
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||In Bolivar, Colombia, Green (1978) estimated a density of 0.5 groups/km² or 1.5 individuals/km². Aquino and Encarnación (1994b) reviewed population structure and densities for the genus.|
|Current Population Trend:||Unknown|
|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, submontane forest (Hernández-Camacho and Cooper 1976; Defler 2003, 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).
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, 1981; 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). 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.
Adult male weight average 1.2 kg (n=1), adult female weight 1.0 kg (n=1) (Fernandes 1993).
|Major Threat(s):||This is a wide-ranging species, and there is no evidence of any particular threat other than habitat loss.|
In Brazil, the species is confirmed, or may occur, in the following protected areas:
Pico da Neblina National Park (2,298,154 ha) (in range)
Rio Trombetas Biological Reserve (409,578 ha) (in range)
Uatumã Biological Reserve (942,786 ha) (in range)
Anavilhanas Ecological Station (343,897 ha) (in range)
Caracaraí Ecological Station (85,957 ha) (in range)
Niquiá Ecological Station (282,830 ha) (in range).
It is listed on Appendix II of CITES.
Aquino, R. and Encarnación, F. 1994. Owl monkey populations in Latin America: field work and conservation. In: J.F. Baer, R.E. Weller and I. Kakoma (eds), Aotus: The Owl Monkey, pp. 59-95. Academic Press, San Diego, CA, USA.
Aquino, R., Puertas, P. E. and Encarnación, F. 1990. Supplemental notes on population parameters of northeastern Perucvian night monkeys, genus Aotus (Cebidae). American Journal of Primatology 21: 215-221.
Bodini, R. and Pérez-Hernández, R. 1987. Distribution of the species and subspecies of cebids in Venezuela. Fieldiana: Zoology 39: 231–244.
Defler, T. R. 2003. Primates de Colombia. Conservation International, Bogota.
Defler, T. R. 2004. Primates of Colombia. Conservation International, Washington, DC, Usa.
Defler, T.R. and Bueno, M.L. 2007. Aotus diversity and the species problem. Primate Conservation 22: 55-70.
Defler, T. R., Bueno, M. L. and Hernández-Camacho, J. I. 2001. Taxonomic status of Aotus hershkovitzi: Its relationship to Aotus lemurinus lemurinus. Neotropical Primates 9: 37–52.
Dixson, A. F. 1983. The owl monkey (Aotus trivirgatus). In: J. P. Hearn (ed.), Reproduction in New World Primates: new Models in Medical Sciences, pp. 69-113. International Medical Publishers, Lancaster, UK.
Fernandes, M. E. B. 1993. New field records of night monkeys, genus Aotus, in northern Brazil. Neotropical Primates 1(4): 6-8.
Fernandez-Duque, E. 2004. High levels of intrasexual competition in sexually monomorphic owl monkeys (Aotus azarai). Foliia Primatologica 75(1): 260.
Fernandez-Duque, E. 2007. Aotinae: Social monogamy in the only nocturnal haplorhines. In: C.J. Campbell, A. Fuentes, K.C. Mackinnon, M. Panger and S.K. Bearder (eds), Primates in Perspective, pp. 139-154. Oxford University Press, Oxford, UK.
Fernandez-Duque, E. and Huntington, C. 2002. Disappearances of individuals from social groups have imolications for understanding natal dispersal in monogamous owl monkeys (Aotus azarai). American Journal of Primatology 57: 219-225.
Ford, S.M. 1994. Taxonomy and distribution of the owl monkey. In: J.F. Baer, R.E. Weller and I. Kakoma (eds), Aotus: The Owl Monkey, pp. 1–57. Alan R. Liss, New York, USA.
Green, K. M. 1978. Primate censusing in northern Colombia: A comparison of two techniques. Primates 19: 537-550.
Hernández-Camacho, J. and Cooper, R. W. 1976. The nonhuman primates of Colombia. In: R. W. Thorington, Jr. and P. G. Heltne (eds), Neotropical Primates: Field Studies and Conservation, pp. 35-69. National Academy of Sciences, Washington, DC, USA.
Hershkovitz, P. 1983. Two new species of night monkeys, genus Aotus (Cebidae, Platyrrhini): A preliminary report on Aotus taxonomy. American Journal of Primatology 4: 209–243.
Juárez, C., Rotundo, M. and Fernandez-Duque, E. 2003. Behavioral sex differences in the socially monogamous night monkeys of the Argentinean Chaco. Revista de Etologia 5: 174.
Linares, O.J. 1998. Mamíferos de Venezuela. Sociedad Conservacionista Audubon de Venezuela, Caracas, Venezuela.
Rotundo, M., Fernandez-Duque, E. and Dixson, A.F. 2005. Infant development and paretnal care in free-rannig groups of owl monkeys (Aotus azarai azarai) in Argentina. International Journal of Primatology 36(6): 1459-1473.
Rotundo, M., Fernandez-Duque, E. and Giménez, M. 2002. Cuidado biparental en el mono de noche (Aotus azarai azarai) de Formosa, Argentina. Neotropical Primates 10: 70-72.
Ruiz-Herrera, A., García, F., Aguilera, M., Garcia, M. and Fontanals, M. 2005. Comparative chromosome painting in Aotus reveals a highly derived evolution. American Journal of Primatology 65: 73–85.
Villavicencio Galindo, J.M. 2003. Distribución geográfica de los primates del género Aotus en el Departamento Norte de Santander, Colomiba. In: V. Pereira-Bengoa, F. Nassar-Montoya and A. Savage (eds), Primatología del Nuevo Mundo, pp. 264-271. Centro de Primatología Araguatos, Bogotá, Colombia.
Wright, P.C. 1978. Home range, activity pattern, and agonistic encounters of a group of night monkeys (Aotus trivirgatus) in Peru. Folia Primatologica 29: 43–55.
Wright, P. C. 1981. The night monkeys, genus Aotus. In: A. F. Coimbra-Filho and R. A. Mittermeier (eds), Ecology and Behavior of Neotropical Primates, Vol. 1, pp. 211-240. Academia Brasileira de Ciências, Rio de Janeiro, Brazil.
Wright, P.C. 1989. The nocturnal primate niche in the New World. Journal of Human Evolution 18: 635-638.
Wright, P.C. 1994. The behavior and ecology of the owl monkey. In: J.F. Baer, R.E. Weller and I. Kakoma (eds), The Owl Monkey, pp. 97-112. Academic Press, San Diego, CA, USA.
|Citation:||Veiga, L.M. & Rylands, A.B. 2008. Aotus trivirgatus. The IUCN Red List of Threatened Species 2008: e.T41543A10496292.Downloaded on 23 October 2017.|