Alouatta pigra, Lawrence, 1933

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Atelidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 484-549 : 533-534

12 .

Central American Black Howler

Alouatta pigra

French: Hurleur paresseux / German: Guatemala-Brullaffe / Spanish: Mono aullador del Yucatan Other common names: Guatemalan Black Howler, Lawrence's Black Howler, Mexican Black Howler, Yucatan Black Howler

Taxonomy. Alouatta pigra Lawrence, 1933 ,

Uaxactun, Petén, Guatemala.

The Central American Black Howler is genetically distinct and is believed to have diverged from A. palliata c.3 million years ago. It is sympatric with A. palliata in Tabasco State, Mexico, and Chocon Machacas Biotope and Mario Dary Rivera Biosphere Reserve in Guatemala. Monotypic.

Distribution. SE Mexico (Tabasco, Campeche, Yucatan, Quintana Roo, and S Chiapas, states), Belize, and N & C Guatemala; the S limits of its distribution are defined by Lago de Izabel, El Golfete, and Rio Dulce in Guatemala.

Descriptive notes. Head-body 65-71 cm (males) and 52-64 cm (females), tail 60- 69 cm (males) and 50-54 cm (females); weight 7-5-9-1 kg (males) and 4-6-7 kg (females); all measurements from Belize. In 1935, A. Murie reported that the largest of three male Central American Black Howlers that he shot in Guatemala weighed 11-1 kg (the only male weight he provided). No individuals have been found that weigh that much since. Fur of the Central American Black Howler is notably long, soft, and dense. Adult males and females are black with traces of brown on shoulders, cheeks, and back. There is a slight crest on the crown; fur comes forward from a whorl on the nape and then suddenly becomes very short and upright, with a slight parting going back to the whorl. Males older than four months have a conspicuous white scrotum.

Habitat. Primary and secondary forest, high-elevation and lowland rainforest, and semi-deciduous evergreen and riparian lowland forest; riparian and seasonally flooded forests are particularly favored. Like the Mantled Howler (A. palliata ), the Central American Black Howleris often seen in the vicinity of Mayan archaeological sites.

Food and Feeding. Diets of Central American Black Howlers vary seasonally. The feeding ecology of two groups was studied by S. Silver and colleagues for a year in the Community Baboon Sanctuary on the banks of the Belize River. They fed on 74 plant species, 53 of which were trees and the remainder epiphytes or lianas. Fruits and young leaves, and, to a lesser extent, mature leaves of nine species of Ficus (Moraceae) were eaten. The average annual diet of the two groups was 40-8% fruits (monthly range 10-5-64-5%), 37-2% young leaves (18:1-64-6%), 10-6% flowers, 7-9% mature leaves (0-2-31-4%), and 3-5% other items such as pulvini (a joint-like thickening at the base of the leaf) and leaf petioles (leaf stalks). Thirty-two percent of their feeding time was dedicated to Ficus (monthly range 6-65% of feeding records). They ate mature leaves from four species: Ficus maxima and FE insipida (both Moraceae ), Sapindus saponaria ( Sapindaceae ), and Cecropia (Urticaceae) . Flowers were an important source of food when fruits were most scarce in the early dry season.

Breeding. Births of Central American Black Howlers occur throughout the year. When a female is receptive, a male follows her around, resting beside her, in contact, and sniffing her urine. Females show anogenital rubbing on a branch, which males sniff with interest. Males put their heads up and rub their chins and chests on branches at this ime. The female gazes at the male and flicks her tongue slowly prior to copulation. Infants are initially carried on the ventrum. Males and females, besides the mother carry young (allomothering). The transfer of young is described as passive: a female approaches and remains near the mother and infant, looking,sniffing, and occasionally touching the infant, and then extends her neck or chest over the infant and coddles it onto her body. Interest from allomothers peaks twice, once when infants are 2-3 weeks old and again when they are 6-10 weeks old. Experienced mothers tend to carry infants more during the first peak, and males and inexperienced females during the second peak. Infants begin to spend more time off their mothers and allomothers at 9-10 weeks old.

Activity patterns. The Central American Black Howler is diurnal and arboreal. A yearlong study in Belize demonstrated that activity patterns are flexible. A typical profile is 61-9% resting (range 50-67-7%), 24-4% feeding (19-1-31-2%), 9-8% resting (6:6-13-5%), 2:3% engaged in social affiliative behaviors (playing and grooming), and 1-6% vocalizing.

Movements, Home range and Social organization. Groups of Central American Black Howlers are unimale—multifemale or multimale—multifemale, with 3-9 individuals. Twenty groups of Central American Black Howlers at Palenque, Chiapas, Mexico (humid, evergreen forest) averaged seven individuals (range 2-12), with 1-4 adult males and 1-4 adult females. Home range sizes were 25-50 ha and varied with group size. Males disperse, and group takeovers by males are violent. Infanticide has been observed following the immigration of a new male and the expulsion of the previous dominant male. In Belize, densities are 8-22 ind/km?. In Tikal, Guatemala, densities are low at 5-9 ind/km?, but they are higher at 16-5 ind/km?*in the Muchukux forest in Quintana Roo and 23 ind/km?* at Palenque, Chiapas, Mexico.

Status and Conservation. CITES Appendix I. Classified as Endangered on The [UCN Red List. The Central American Black Howler continues to decline in numbers because of severe loss of habitat over much of its range. It is still occasionally hunted, and suffers from yellow fever epidemics and hurricanes. It can reach very high numbers when not hunted, even near human settlements. A remarkable initiative for their conservation is that of the Community Baboon Sanctuary in Belize, where a pioneer program of community land management with subsistence farmers has been set up to specifically accommodate the needs of the Central American Black Howler. Management agreements guarantee permanence of mosaics and corridors of forests, including riparian forest, and leave intact key food resources of howlers, while allowing for the traditional slash-and-burn agriculture by local villagers. Effective ladder bridges have been put in place where roads separate the forest canopy. In 1990, the Sanctuary included more than 100 people in seven villages over an area of more than 46 km? and the program has grown since then. From 1985 (when the program began) to 1999, the population of Central American Black Howlers grew by 8-9 ind/year, from 840 to more than 2000 individuals. The density estimate in 1999 was 178 ind/km?®. Villagers have also benefitted from tourists interested in seeing howlers.

Bibliography. Arrowood et al. (2003), Baumgarten & Williamson (2007), Bolin (1981), Brockett et al. (1999), Cortés-Ortiz et al. (2003), Ellsworth & Hoelzer (2006), Estrada & Coates-Estrada (1984, 1988), Estrada, Castellanos et al. (2002), Estrada, Coates-Estrada et al. (2000), Estrada, Luecke, Van Belle, Barrueta & Meda (2004), Estrada, Luecke, Van Belle, French et al. (2002), Horwich (1983a, 1983b, 1998), Horwich & Gebhard (1986), Horwich & Johnson (1986), Horwich et al. (1993), Jones & Young (2004), Lawrence (1933), Murie (1935), Ostro et al. (1999), Pavelka & Knopff (2004), Pavelka et al. (2003), Richard (1970), Rylands et al. (2006), Silver et al. (1998), Smith (1970), Van Belle et al. (2010).

Figures

On followıng pages Mantled Howler (Alouatta palliata) 12 Central Amerıcan Black Howler (Alouatta pigra)

Distribution. SE Mexico (Tabasco, Campeche, Yucatan, Quintana Roo, and S Chiapas, states), Belize , and N & C Guatemala ; the S limits of its distribution are defined by Lago de Izabel, El Golfete, and Rio Dulce in Guatemala .