Artibeus obscurus (Schinz, 1821)

Don E. Wilson & Russell A. Mittermeier, 2019, Phyllostomidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 444-583 : 574

194.

Dark Fruit-eating Bat

Artibeus obscurus

French: Artibée noiratre / German: Dunkler Fruchtvampir / Spanish: Artibeo oscuro

Other common names: Dark Artibeus

Taxonomy. Phyllostoma obscurum Schinz, 1821 ,

“Ostkuste von Brasilien.” Identified by M. P. zu Wied-Neuwied in 1826 as “Villa Vicosa [= Maroba] am Flusse [= River] Peruhype,” Bahia, Brazil.

Artibeus obscurus is in subgenus Artibeus . J. E. Gray in 1838 used Arctibeus fuliginosus to describe the black-furred Artibeus , type locality “S. America,” although later both names were considered as nomina dubia. M. D. Tuttle in 1970 suggested that fruit eating bats from Amazonian Peru, formerly referred to as A. jamaicensis , belong to two or more distinct species; an “unrecognized” species was distinguished by its smaller size and darker pelage and was referred to as A. fuliginosus to distinguish it from A. jamaicensis and A. lituratus . At various points,it was proposed that fuliginosus should be considered a subspecies of A. jamaicensis , or obscurus should be the name applied to the dark-colored Artibeus . K. F. Koopman in 1993 recognized A. fuliginosus as a synonym of A. obscurus . Several molecular studies have suggested geographical structuring within and among populations of A. obscurus , including potential species-level variation coupled with morphological distinctions that seem to correspond to different ecodomains or regions. Monotypic.

Distribution. E of Andes in E Colombia and E & S Venezuela (S of the Llanos), E lowlands of Ecuador, Peru, and N Bolivia, and through the Guianas into most of Brazilian Amazon (considered as the center of its distribution) and E & SE Brazil.

Descriptive notes. Head—body 72-90 mm (tailless), ear 20-24 mm, hindfoot 13-19 mm, forearm 52-65 mm; weight 28-52-5 g. Greatest lengths of skulls are 26-29-5 mm. Females are slightly larger than males, but sexual dimorphism is not certain. The Dark Fruit-eating Bat is the smallest species of Amazonian Artibeus . Dorsal fur is sooty or blackish brown to dark brown, and underparts are slightly paler and always white-tipped, giving a frosted appearance. Fur is soft and long on back, neck, and shoulders (more than 8 mm). Facial stripes are faint or absent. Ears, tragus, and noseleaf are blackish, contrasting with fairly pale fur of head. Bases of dorsal and ventral sides of forearms are hairy. Tibia and foot are almost naked. Uropatagium is broad and sparsely haired to naked. Ears are far apart and naked. Noseleaf is ovate-lanceolated and surrounded on base by numerous long vibrissae, and lower rim of horseshoe is not attached to lip. Chin has fewer and smaller ornamental warts (5-6 on each side). Lips are fringed. Iris is a characteristic brown. Skull is relatively long, with shallow rostrum;crests, preorbital, and postorbital processes are poorly developed. M? is usually present and occurs in more than 90% of Dark Fruit-eating Bats north of the Amazon and almost 80% south of the Amazon. Dental formulais12/2,C1/1,P 2/2, M 2-3/3 (x2) = 30 or 32. M? are usually present and small. Chromosomal complement has 2n = 30 (females) and 31 (males) and FN = 56.

Habitat. [Lowland and montane primary rainforests and secondary habitats of the Amazon Basin to savannas and semideciduous forests of eastern Bolivia and southern Brazl from sea level up to elevations of ¢. 1660 m (mostly below 500 m). Specific habitats of the Dark Fruit-eating Bat include well-drained primary forests, creek-side primary forests, pre-montane humid forests, lower montane humid forests, palm groves, orchards, croplands, pastures, and yards. It is rarely found in cloud forests.

Food and Feeding. The Dark Fruit-eating Bat belongs to the high-flying frugivore guild. Little is known aboutits diet, but it apparently eats fruit of several canopy trees, including Ficus (Moraceae) , Inga (Fabaceae) , Pourouma (Urticaceae) , and other tall plant species characteristic of mature Neotropical forests. There are records offigs ( Ficus ) being carried in Colombia, Peru, and Brazil. It has been proposed that the reason for its rare capture records in small fragments and secondary forests is due to differences in the spatiotemporal distribution and density oftall fruit trees in these habitats compared with larger mature forests. A study in Atlantic Forest fragments formed by a mosaic of vegetation in Mina Gerais , Brazil found that the Dark Fruit-eating Bat used Piper (Piperaceae) and Cecropia (Urticaceae) trees, along with Seba’s Short-tailed Bats ( Carollia perspicillata ), Fringed Fruit-eating Bats (A. fimbriatus ), Great Fruit-eating Bats (A. lLturatus), and Little Yellow-shouldered Bats ( Sturnira lilium ). Frequency of bats near mineral licks, called “colpas” or “saladeros,” in the Yasuni tropical rainforest in eastern Ecuador suggest that frugivorous species like the Dark Fruit-eating Bat, and especially reproductive females, obtain minerals in running water at these licks, which might provide offspring with calcium and other nutrients and also protect them from toxic substances in some fruits that they eat.

Breeding. Scarce information on reproduction suggests a pattern of bimodal polyestry. Pregnant Dark Fruit-eating Bats have been collected in February—-May in Venezuela and Para, Brazil, and July-November in Peru, Venezuela, and Mato Grosso, Brazil. In Bolivia, pregnant females were recorded in May and July, and non-pregnant females were recorded in March-April, June-July, and December. In Ecuador, mating occurs in September-November, embryonic development occurs until about March, and lactation starts in April, although lactating and pregnant females were also found in February—March. In Peru, pregnant and non-pregnant females and reproductive males with scrotal testes have been captured in August.

Activity patterns. The Dark Fruit-eating Bat is nocturnal and mainly active in late evening. Observation from Minas Gerais, south-eastern Brazil, suggest that it has a general activity pattern consisting of one high peak in the first 2-3 hours of the night followed by decreasing activity in the next few hours and a second peak during the fifth hour of the activity interval. It roosts in cavities in standing trees, crevices in rocks, caves, and man-made structures and under unmodified foliage, showing preference for more ephemeral shelters that are susceptible to changes in temperatures and humidity. Although similar, distress calls of the Dark Fruit-eating Bat are distinctive from those of the Flat-faced Fruit-eating Bat ( A. planirostris ) and resemble those of the Great Fruiteating Bat; they are used to signify danger to conspecifics.

Movements, Home range and Social organization. Groups of Dark Fruit-eating Bats have been observed in Paracou, French Guiana. One group consisted of an adult female with her nursing young and a second group consisted of an adult female, her nursing young, and another adult of unknown sex clustered beneath a lose piece of bark c. 6 m aboveground on the tree trunk. A solitary near-term pregnant female (no date defined) and a solitary adult male were found roosting c. 4 m aboveground under an unmodified leaf in tall tree.

Status and Conservation. Classified as Least Concern on The [UCN Red List. The Dark Fruit-eating Bat is very common and has a wide distribution through most of eastern South America.

Bibliography. Aguiar & Marinho-Filho (2004, 2007), Albuja (1999), Anderson (1997), Brosset & Charles-Dominique (1991), Davis & Dixon (1976), Faria (2006), Ferreira et al. (2014), Garbino & Tavares (2018), Gray (1838), Handley (1976, 1990), Haynes & Lee (2004), Koepcke & Kraft (1984), Koopman (1993), Larsen et al. (2010b), Lim & Wilson (1993), Lim, Engstrom, Lee et al. (2004), Marques-Aguiar (1994, 2008a), Patterson et al. (1996), Pumo et al. (1996), Redondo et al. (2008), Simmons & Voss (1998), Tuttle (1970), Voigt etal. (2008), Wied-Neuwied (1826).

Figures

187. Brown Fruit-eating Bat (Artibeus concolor), 188. Honduran Fruit-eating Bat (Artibeus inopinatus), 189. Fraternal Fruit-eating Bat (Artibeus fraterculus), 190. Hairy Fruit-eating Bat (Artibeus hirsutus), 192. Ecuadorian Fruit-eating Bat (Artibeus aequatorialis), 193. Jamaican Fruit-eating Bat (Artibeus jamaicenss), 194. Dark Fruit-eating Bat (Artibeus obscurus), 195. Schwartz’s Fruit-eating Bat (Artibeus schwartzi), 196. Great Fruit-eating Bat (Artibeus lLituratus), 197. Large Fruit-eating Bat (Artibeus amplus), 198. Flat-faced Fruit-eating Bat (Artibeus planirostris), 199. Rosenberg’s Fruit-eating Bat (Artibeus rosenberg), 200. Thomas's Fruit-eating Bat (Artibeus watsoni), 201. Toltec Fruit-eating Bat (Artibeus toltecus), 202. Pygmy Fruit-eating Bat (Artibeus phaeotis), 203. Gervais’s Fruit-eating Bat (Artibeus cinereus), 204. Andersen’s Fruit-eating Bat (Artibeus anderseni), 205. Little Fruit-eating Bat (Artibeus ravus), 206. Aztec Fruit-eating Bat (Artibeus aztecus), 207. Bogota Fruit-eating Bat (Artibeus bogotensis), 208. Silvery Fruit-eating Bat (Artibeus glaucus), 209. Dwarf Fruit-eating Bat (Artibeus gnomus), 210. Jamaican Fig-eating Bat (Ariteus flavescens), 211. Tree Bat (Ardops nichollsi), 212. Red Fruit Bat (Stenoderma rufum), 213. Wrinkle-faced Bat (Centurio senex), 214. Ipanema Broad-nosed Bat (Pygoderma bilabiatum), 215. Visored Bat (Sphaeronycteris toxophyllum), 216. Little White-shouldered Bat (Ametrida centurio), 217. Cuban Fig-eating Bat (Phyllops falcatus)

Distribution. E of Andes in E Colombia and E & S Venezuela (S of the Llanos), E lowlands of Ecuador , Peru , and N Bolivia , and through the Guianas into most of Brazilian Amazon (considered as the center of its distribution) and E & SE Brazil .