Aotus azarae 

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Aotidae

Scientific Name: Aotus azarae (Humboldt, 1811)
Infra-specific Taxa Assessed:
Common Name(s):
English Azara’s Night Monkey
Spanish Cuatro Ojos, Mono Nocturno
Aotus azarai Lahille, 1898
Pithecia miriquouina É. Geoffroy Saint-Hilaire (1812)
Simia azarae Humboldt (1811)
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.

Hershkovitz (1983) recognized the form infulatus Kuhl, 1820 as a full species, whereas Groves (2001, 2005) placed it as a subspecies: Aotus azarae infulatus (Kuhl, 1820).

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Fernandez-Duque, E., Wallace, R.B. & Rylands, A.B.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This is species is listed as Least Concern because even though deforestation is occurring throughout many parts of its range (particularly in Brazil), the population is not believed to be declining fast enough to qualify for a more threatened category. However, agricultural development for soy and other products represents a growing threat for this species.
Previously published Red List assessments:

Geographic Range [top]

Range Description:There are three recognized subspecies:

A. azarae azarae occurs in the southern and western Chaco region of Paraguay (excluding the the extreme west, where no primates occur), west of the Rio Paraguai, and extending across the Río Pilcomayo to south of the Río Bermejo to the Rio Negro in the provinces of Formosa and Chaco in Argentina (Rathbun and Gache 1980; Hershkovitz 1983; Stallings 1985, 1989; Zunino et al. 1986; Stallings et al. 1989). In the west, its range extends to the Cordillera Oriental, but its range in the north is not clearly delimited. Following Hershkovitz (1983), it would seem to extend to the Bañado do Izozog in Bolivia.

Aotus azarae boliviensis occurs south of the Río Madre de Dios, as far west as the Río Inambari in Peru (Aquino and Encarnación 1994a), extending along the Cordillera Oriental in Bolivia to southern Bolivia where it meets the range of A. azarae azarae in the region of the Bañado de Izozog. To east it occurs as far as the Rio Guaporé and the border with Brazil. It is not known if it occurs in Brazil in the state of Mato Grosso do Sul.

Aotus azarae infulatus occurs in at least a small section of the southern Amapá (Carmo de Macacoari, municipality of Itaubal) and on the Islands of Marajó and Caviana (Hill 1960; Fernandes 1993; Silva et al. 1995) possibly Gurupá and Mexiana. From there it occurs the south of the Rio Amazonas, west to the Rios Tapajós and Juruena, in the south along the right banks of the Guaporé, to the east of the Rio Corixá Grande, as far as the Rio Itiguira, a tributary of the Rio Paraguai. In the east its range is delimited by the left bank of the Rio Paranaiba to its headwaters and from there to the east of the Rio Manuel Alves Grande (a tributary of the Rio Tocantins) to the Rio Tocantins, and from there restricted to the west (left bank) of the river.
Countries occurrence:
Argentina (Chaco, Formosa); Bolivia, Plurinational States of; Brazil (Maranhão, Mato Grosso, Pará, Tocantins); Paraguay; Peru
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Across its range, it is relatively common, but it is usually ignored in primate abundance surveys due to its nocturnal and crepuscular behaviour. Few reliable estimates of population density are available for any of the subspecies. Aquino and Encarnación (1994b) reviewed population structure and densities for the genus.

A. a. azarae:
In eastern Formosa (Guaycolec), densities can be as high as 60 individuals/km² in gallery forests (Fernandez-Duque et al. 2001). Relatively lower densities have been estimated elsewhere in Formosa: 12.8-29.0 individuals/km² (see Fernandez-Duque 2007).
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). In the Chaco, Aotus a. azarae occurs in dry, semideciduous forest patches and gallery forest, where annual rainfall can be as low as 500 m a year (Wright 1985; Stallings et al. 1989; Brooks 1996; Fernandez-Duque et al. 2002). Aotus a. boliviensis is found in semi-deciduous and evergreen lowland forests in Bolivia and up to at least 1,250 m in some parts of the Andes. Aotus a. infulatus extends through lowland evergeen forests in southern Pará and northern Mato Grosso, through forest patches and gallery in the Cerrado (bush savanna) into the Pantanal of Mato Grosso. 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 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). García and Braza (1987) recorded a home range of 1.3 ha for A. a. boliviensis in Beni, Bolivia. Arditi (1992) estimated a home range 12 ha for A. a. azarae in Guaycolec, Formosa, Argentina. 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).

Aotus azarae azarae
Adult male weight average 1.254±0.118 kg (n=40, range 0.99-1.58 kg), adult female weight average 1.246±0.114 kg (n=39, range 1.01-1.45 kg) (Fernandez-Duque 2004)
Aotus azarae boliviensis
Adult male weight average 1.18 kg (n=4), adult female weight 1.23 (n=8) (Smith and Jungers 1997)
Aotus azarae infulatus
Adult male weight average 1.19 kg (n=1), adult female weight 1.24 (n=1) (Fernandes 1993).

Threats [top]

Major Threat(s): Aotus azarae azarae and A. a. boliviensis:
Threats to these subspecies include habitat loss due to agricultural development for soy and cattle ranching in Brazilian cerrado, soy in the Bolivian Chiquitano, and small-scale farms and cattle ranching in Argentina. Minimal subsistence hunting occurs in Bolivia, for consumption and bait for fishing.

Aotus a. infulatus:
Much forest destruction and fragmentation is occurring in its range in southern Pará and northern Mato Grosso.

Conservation Actions [top]

Conservation Actions: This species is confirmed, or may occur, in many national parks, several of which are quite large. It is listed on Appendix II of CITES.

Aotus azarae azarae

Plicomayo National Park

Kaa-Iya Gran Chaco National Park (3,441,115 ha)
Estación Biológica Beni (135,000 ha) (Garcia and Tarifa 1988)

Tinfunque National Park
Defensores del Chaco National Park (780,000 ha) (Stallings 1985, 1989)

Aotus azarae boliviensis

Isiboro Secure National Park (1,200,00 ha) (Brown and Rumiz 1986)
Noel Kempff Mercado National Park (1,500,00) (Wallace et al. 1998))
Pilón Lajas National Park (400,000 ha) Brown and Rumiz 1986)
Amboró National Park (180,000 ha) (Brown and Rumiz 1986)
Carrasco Ichilo National Park (622,600 ha) (in range)
Madidi National Park(1,571500 ha) (in range)

Aotus azarae infulatus
Araguaia National Park (557,726 ha) (in range)
Pantanal Matogrossense National Park (136,046 ha) (in range)
Gurupi Biological Reserve (272,379 ha) (in range)
Tapirapé Biological Reserve (99,703 ha) (in range)
Tapajós National Forest (600,000 ha) (in range)

Classifications [top]

1. Forest -> 1.5. Forest - Subtropical/Tropical Dry
suitability:Suitable  major importance:Yes
1. Forest -> 1.6. Forest - Subtropical/Tropical Moist Lowland
suitability:Suitable  major importance:Yes
1. Forest -> 1.8. Forest - Subtropical/Tropical Swamp
suitability:Suitable  major importance:Yes
2. Savanna -> 2.1. Savanna - Dry
suitability:Suitable  major importance:Yes
2. Land/water management -> 2.1. Site/area management
3. Species management -> 3.1. Species management -> 3.1.1. Harvest management

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Conservation sites identified:Yes, over entire range
In-Place Species Management
In-Place Education
  Included in international legislation:Yes
  Subject to any international management/trade controls:Yes
2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.3. Agro-industry farming
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

2. Agriculture & aquaculture -> 2.3. Livestock farming & ranching -> 2.3.3. Agro-industry grazing, ranching or farming
♦ timing:Ongoing    
→ Stresses
  • 1. Ecosystem stresses -> 1.1. Ecosystem conversion
  • 1. Ecosystem stresses -> 1.2. Ecosystem degradation

1. Research -> 1.1. Taxonomy
1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
1. Research -> 1.6. Actions
3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓ 

Bibliography [top]

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Aquino, R. and Encarnación, F. 1994. Primates of Peru / Los Primates del Perú. Primate Report 40: 1-127.

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Citation: Fernandez-Duque, E., Wallace, R.B. & Rylands, A.B. 2008. Aotus azarae. In: . The IUCN Red List of Threatened Species 2008: e.T41539A10494975. . Downloaded on 22 May 2018.
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