Alouatta seniculus ssp. puruensis
|Scientific Name:||Alouatta seniculus ssp. puruensis Lönnberg, 1941|
Alouatta puruensis Lönnberg, 1941
|Taxonomic Notes:||Hill (1962) and Stanyon et al. (1995) listed nine subspecies of the Red Howler Monkey, Alouatta seniculus: A. s. seniculus, A. s. arctoidea, A. s. stramineus, A. s. macconnelli, A. s. insulanus, A. s. amazonica, A. s. juara, A. s. puruensis, and A. s. sara.
Alouatta seniculus puruensis Lönnberg, 1941, from Jaburú, Rio Purus, is recognized as a distinct form by Gregorin (2006). He indicated that it occurs along the Ruo Purus basin and adjacent parts of the upper Rio Madeira (at least south from the lower Rio Aripuanã, about 10°S) into Rondônia. The southernmost record is Plácido de Castro, Acre. Groves (2001, 2005) placed it as a junior synonym of A. s. juara.
This taxon was treated as a full species in the 2008 Red List, but from the 2015.2 update was treated as a subpspecies of A. seniculus.
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Boubli, J.-P., Di Fiore, A., Rylands, A.B. & Mittermeier, R.A.|
|Reviewer(s):||Mittermeier, R.A., Rylands, A.B. & Hoffmann, M.|
This subspecies is listed as Least Concern given its widespread distribution and lack of apparent major threats believed to be resulting in a significant decline that would warrant listing the taxon in Near Threatened or a threatened category. Further survey work is needed to clarify the distribution limits of the taxon relative to A. sara in Bolivia.
|Previously published Red List assessments:|
|Range Description:||This red howler monkey extends west from the lower Rio Madeira (left bank) and the Rio Aripuanã across the basin of the Rio Purus to the Rios Juruá and Envira, as postulated by Gregorin (2006). It occurs in northern Rondônia, but the southern limits to its range in Brazil are unclear. It is not clear whether it is the form in north-west Bolivia and far south-eastern Peru in the basins of the upper Purus, Madre de Dios and Tampopata. According to Anderson (1997), only Alouatta sara occurs in Bolivia. Aquino and Encarnacion (1994a) did not consider subspecies or any species other than A. seniculus. Red howlers occur throughout the Peruvian Amazon from the Río Inamabari in the far south-east, along the Rio Urubamba, through the Pachitea to the right (east) bank of the Rio Huallaga, north accompanying the Cordillera to cross the Río Marañón, extending into Ecuador along the Río Santiago (left bank). According to Gregorin (2006), the west (left) bank the Rio Juruá and Envira is taken up by A. seniculus juara. For this reason, the Río Inuya may be the northern limit to A. seniculus puruensis in Peru.|
Native:Brazil (Acre, Amazonas, Mato Grosso, Rondônia); Peru
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Peres (1997) estimated population densities of howler monkeys at a number of sites on the right (east) bank of the Rio Juruá (presumably A. seniculus puruensis): Vai Quem Quer (terra firma forest), 1.0 individuals/km²; Igarapé Jaraquí (terra firma forest), 5.5 individuals/km²; Penedo (terra firma forest), 2.6 individuals/km²; Boa Esperança (várzea), 89.7 individuals/km². Peres (1997) found that populations were higher in várzea (seasonally inundated) forests than in terra firma forests.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||This subspecies is found in lowland, evergreen rain forest. Along the Rio Juruá, and undoubtedly elsewhere in its range, it tends to be more common in seasonally flooded forest (várzea) than in terra firma forest (Peres 1997).|
The howler monkeys are the large leaf-eaters of the South American primate communities. The molar teeth are particularly adapted for their chewing leaves through shearing. They spend up to 70% of their day lying and sitting about quietly among the branches, fermenting leaves in their enlarged caecums. Like the spider monkeys, they are prehensile-tailed, with a naked patch of skin on the under surface at the tip. Their most characteristic feature is the deep jaw which surround the enlarged larynx and hyoid apparatus, a resonating chamber. It is with this enlarged and highly specialized voice box that they produce their howls (grunts, roars and barks). Howling sessions, usually involving the entire group, can be heard particularly in the early morning and are audible at distances of 1-2 kms (Drubbel and Gautier 1993).
Red howler groups are usually small, ranging in size from 2-16 animals and averaging 4-10 (Neville et al. 1988). There is usually only one dominant male in the group (occasionally two), others being sub-adults, or juveniles, along with a harem of two to five females. Unlike the spider monkeys, and related to the large proportion of leaves in the diet (up to 50% of the annual diet), the howler monkeys generally have quite small and broadly overlapping home ranges, of 5 ha up to 45 ha, depending on the type of habitat (Neville et al. 1988). The large groups of A. palliata may have home ranges extending to 60 ha (Estrada 1982), whereas in the llanos of northern Venezuela, home ranges of A. arctoidea can be as small as 4 ha (Sekulic 1982a).
Howlers are the only New World primates which regularly include mature leaves in their diet, although softer, less fibrous, young leaves are preferred when they are available. Their folivory and ability to eat mature leaves is undoubtedly one of the keys to their wide distribution and the wide variety of vegetation types they inhabit. Mature fruit is the other important food item, especially wild figs (Ficus) in many regions, but they also eat leaf petioles, buds, flowers (sometimes seasonally very important), seeds, moss, stems and twigs, and termitaria.
Oestrus lasts 2-4 days, with intervals between oestrous periods of about 17 days. Interbirth intervals are generally about 16.6 months, although they may be shortened by the death of an infant to about 10.5 months (Crockett and Sekulic 1984). Mean gestation length is 191 days (range 186-194, n=6) (as for A. seniculus seniculus in Crockett and Sekulic 1982)
As for Alouatta seniculus, Brazil
Adult male 7.62 kg (n=28) (Ayres 1986)
Adult female 6.02 kg (n=34) (Ayres 1986).
|Major Threat(s):||No major threats across the range, although habitat loss and hunting are no doubt taking place. Aquino and Encarnación (1994a) reported that populations of red howlers have declined in the lower parts of the selva alta in the Peruvian Amazon as a result of colonization by humans, hunting and deforestation, noting particularly the valley of Chanchamayo (Department of Junín) where they have been extirpated.|
|Conservation Actions:||In Brazil, this species is present in Mapinguari National Park (1,572,422 ha), Abufari Biological Station (288,000 ha), and Piagaçu-Purus State Sustainable Development Reserve (1,008,167 ha). It is listed on CITES Appendix II.|
|Citation:||Boubli, J.-P., Di Fiore, A., Rylands, A.B. & Mittermeier, R.A. 2015. Alouatta seniculus ssp. puruensis. The IUCN Red List of Threatened Species 2015: e.T136787A81229559.Downloaded on 24 September 2017.|
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