Alouatta guariba
Creators: name: Russell A. Mittermeier
name: Anthony B. Rylands
name: Don E. Wilson
Publisher: name: Lynx Edicions
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Primates
Atelidae
Alouatta
Alouatta guariba

description: 9.
Brown Howler
Alouatta guariba
French: Hurleur brun / German: Brauner Brillaffe / Spanish: Mono aullador pardo Other common names: Brown Howler/Howling Monkey; Northern Brown Howler (guariba), Southern Brown Howler (clamitans)
Taxonomy. Simia guariba Humboldt, 1812,
Brazil. Restricted by Cabrera in 1957 to the Rio Paraguacu, Bahia.
The taxonomy of A. guariba is poorly understood. It is phenotypically variable and descriptions of the pelage color and patterns are insufficient to identify them in the wild. The validity of separating northern and southern populations as distinct subspecies is hampered by its extreme rarity in the northern part ofits distribution, supposedly the domain of the nominate subspecies. Following his study of cranial morphology and pelage patterns of the Brazilian howlers, R. Gregorin in 2006 argued that the two subspecies of the Brown Howler should be considered as distinct species. He used the name fusca of E. Geoffroy Saint-Hilaire in preference to Humboldt's guariba, indicating that the name guariba is a junior synonym of A. belzebul. Molecular genetic studies by E. Harris and colleagues in 2005 identified distinct haplotypic groups in the southern part of the distribution: one in the states of Rio Grande do Sul and Santa Catarina and the other in the states of Espirito Santo and Rio de Janeiro. It is possible that these represent two subspecies or even distinct species. Two subspecies recognized.
Subspecies and Distribution. A. g. guariba Humboldt, 1812 — Brazilian Atlantic Forest from the Rio Sao Francisco (although the Rio Paraguacu is the northernmost known locality) to the Rio Doce; however, based on his studies of morphology and pelage color patterns Gregorin in 2006 indicated that it extends from the Rio Paraguacu in Bahia State, S along the coast across the lower Rio Jequitinhonha extending inland somewhat into Minas Gerais State, S through the Rio Doce valley as far the Rio Paraiba do Sul Basin in Rio de Janeiro. A. g. clamitans Cabrera, 1940 — Brazilian Atlantic Forest S of Rio Doce (but Gregorin has recently identified howlers of the upper Rio Doce, Rio Matip6 and Caratinga, and the middle and upper Rio Jequitinhonha as marking the N limits of this subspecies) through the S of Espirito Santo to Rio de Janeiro, Sao Paulo, Parana, Santa Catarina, and Rio Grande do Sulstates (S limit is Rio Camaqua Basin in Rio Grande do Sul, 31° 10” S, where the Atlantic Forest gives way to the Pampas grasslands), and inland in the forested E of Minas Gerais (“Zona da Mata”) and the Brazilian Highlands; also in NE Argentina (E of the Mts in Misiones Province to ¢.28° S).
Descriptive notes. Head-body 50-60 cm (males) and 44-54 cm (females), tail 52- 67 cm (males) and 48-57 cm (females); weight 5-3-7-2 kg (males) and 4-1-5 kg (females). The Brown Howleris black or dark brown to reddish above, with the fur having a rather golden sheen to it. There is a triangular or transverse crest toward the front of the crown, where forward-pointing crown hairs meet short, backward-pointing forehead hairs. A heavy facial beard is present in both sexes. Females are generally paler overall. The “Northern Brown Howler” (A. g. guariba) is not sexually dichromatic; both sexes are normally red-fawn, with females usually somewhat duller in color. Males from Minas Gerais are brown with an orange-brown rump, and females are yellow-brown. The “Southern Brown Howler” (A. g. clamitans) is generally dark reddish-brown. Males tend to be lighter colored than females. Males from Sao Paulo are orange-red to redbrown with a red belly, while males from Santa Catarina and Rio Grande do Sul are bright red-orange, with dark brown feet. Females are dark brown or blackish, or with the back frosted with orange or yellow-brown.
Habitat. Lowland, submontane, evergreen, and semi-deciduous, seasonal, and secondary Atlantic coastal forest, including Araucaria (Araucariaceae) pine forest in the southern part of the distribution in Parana, Santa Catarina, and Rio Grande do Sul, from sea level to elevations of 700 m; not found in mangrove forests. Brown Howlers prefer to live in the vicinity of streams, and although they mainly use the upper forest canopy, they frequently descend to the ground to drink.
Food and Feeding. A year-long study by S. Mendes in 850-ha forest in the Caratinga Biological Station in Minas Gerais, Brazil, showed that the diet of the Brown Howler was largely folivorous, but seasonal. In the dry season, leaves accounted for 77-7% of the feeding records, flowers 10-9%, buds 10%, and fruits 1-4%. In the wet season, leaves accounted for 63-5%, fruits 29-8%, flowers 5-8%, and buds 0:9%. In the dry season, leaves in the diet were mostly mature (67-7%), with young leaves accounting for only 6:5% (25-7% undetermined). In the wet season, mature leaves accounted for 30-4% and young leaves 48-7%. Insect foraging was not observed, although insects were certainly eaten along with fruits and leaves. Another study by A. Chiarello in a 250-ha seasonal, semi-deciduous secondary forest in the Mata de Santa Genebra Reserve, near Campinas in Sao Paulo also recorded a high percentage of leaves (73%) in the diet, with flowers accounting for 13% and fruits 6% (8% unidentified). Sixty-eight plant species were included in the diet. Fruits were a consistently small part of the diet throughoutthe year, but flowers assumed a greater importance (24-5% ofthe diet) in the dry season. At least 59% of the leaves in the diet were young. Brown Howlers were very selective and ate leaves from relatively few species. Predominant species were Celtis iguanaea (Ulmaceae), Aspidosperma polyneuron (Apocynaceae), and three members of the Fabaceae, Cassia ferruginea, Inga uruguayensis, and Piptadenia gonoacantha. A study in less diverse Araucaria (Araucariaceae) pine forest in the municipality of Balsa Nova, Parana, by J. Miranda recorded 34 plant species in the diet. Leaves accounted for 57-3%, fruits 41%, and flowers 1-7% of the feeding records during one year. Ocotea (Laureaceae) was important for fruits and leaves and, as had been found in a study in Rio Grande do Sul by R. Silveira, Brown Howlers also ate fruits of exotic cultivated trees, such as Diospyros kaki (caqui, Ebeneceae) and Eriobotrya japonica (loquat, Rosaceae). A similar diet was noted in seasonal, semi-deciduous forest at Ibipora, Parana in a study by L. Aguiar and colleagues: 50-5% leaves, 47-9% fruits, 1-4% flowers, and 0-2% stems.
Breeding. Births of Brown Howlers occur throughout the year. Gestation is reported to be 190 days, with an interbirth interval of 21 months. Based on observations at Balsa Nova, an infant is first carried ventrally. After one month, it begins to move onto its mother’s back. Even in the first month,it leaves its mother momentarily, but serious independent exploration is seen only, and rather suddenly, from the fourth to fifth months. When an infant is four months old, it spends ¢.20% ofits time exploring, but by the fifth month, this increases to almost 90%, with relatively little interaction with its mother. When an infant Brown Howler was two months old, it was sometimes carried by other group members, including a juvenile male, a subadult male, and an adult female. Tidbits of solid food were eaten in the second month, when it also hung from a branch with its prehensile tail for the first time. At two months of age,it also drank from a puddle alongside its mother. Play with a juvenile was seen when the infant was four months old. Males are sexually mature at c.61 months and females at c.43 months.
Activity patterns. Daily activity patterns of Brown Howlers vary, with 10-21% of the time spent feeding, 56-77% resting, 11-24% traveling, and 1-4% in social activity.
Movements, Home range and Social organization. Unimale—unifemale and multimale—-multifemale groups of Brown Howlers have been reported. Groups generally have 5-11 individuals, with 1-3 adult males and 1-4 adult females. Nineteen groups in Caratinga Biological Station had 3-10 individuals (average 6-8). Twenty-five groups at Serra da Cantareira in Sao Paulo averaged 5-8 individuals. Home ranges were 10- 33 ha, and daily movements were 15-1564 m.
Status and Conservation. CITES Appendix II. Classified as Least Concern on The [UCN Red List, including the subspecies clamitans, but the nominate subspecies guariba is classified as Critically Endangered. The conservation status is confused because exact distributional limits of Southern and Northern brown howlers are not clearly understood. Although Brown Howlers occur in the Atlantic Forests of Brazil and northeastern Argentina, a region with a high rate of historical forest loss, it remains widely distributed,is present in many protected areas, and is not declining at a rate sufficient to qualify for a threat category. It is probable that the Brown Howler extended north as far as the Rio Sao Francisco in the past, but it has been entirely extirpated from the northern part of its former distribution. Today, the northern limit is forests remaining in southern Bahia where it is found in small numbers in just a handful of localities. Primary threats are widespread forest loss and fragmentation, hunting for its meat in some areas, and disease epidemics (yellow fever brought from Africa). Nevertheless, the Brown Howler is able to survive in even quite small forest fragments if there is no hunting. Selective logging for prized Araucaria pine is a threat in the southern part of its distribution. In Rio Grande do Sul, itis an important “flagship” species for conservation of the state’s remaining forests and even protection of forest patches in the urban district of the capital, Porto Alegre.
Bibliography. Aguiar, Mellek et al. (2007), Aguiar, dos Reis et al. (2003), Chiarello (1994, 1995a, 1995b, 1999), Chiarello & Galetti (1994), Cordeiro da Silva (1981), Crespo (1954), Di Bitetti (2003b), Di Bitetti & Janson (2000), Galetti et al. (1994), Gregorin (2006), Gregorin et al. (2008), Harris et al. (2005), Hill (1962), Hirsch (2008), Mendes (1989), Miranda & Passos (2004, 2005), Miranda et al. (2005), Oliveira et al. (1995), Pinto et al. (1993), Prates et al. (1990), Printes, Buss et al. (2010), Printes, Liesenfeld & Jerusalinsky (2001), Rylands & Brandon-Jones (1998), Rylands, da Fonseca et al. (1996), Rylands, Spironelo et al. (1988), Silveira & Codenotti (2001), Strier et al. (2001).
description: Published as part of Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Atelidae, pp. 484-549 in Handbook of the Mammals of the World – Volume 3 Primates, Barcelona :Lynx Edicions on page 531, DOI: 10.5281/zenodo.5727205