Sturnira magna, de la Torre, 1966

Don E. Wilson & Russell A. Mittermeier, 2019, Phyllostomidae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 444-583 : 548

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Sturnira magna


135. View Plate 41: Phyllostomidae

Greater Yellow-shouldered Bat

Sturnira magna

French: Grande Sturnire / German: Grof3e Gelbschulterfledermaus / Spanish: Sturniro gigante

Taxonomy. Sturnira magna de la Torre, 1966 ,

“Santa Cecilia (100 m), Rio Maniti, Iquitos, Department of Loreto, Peru.”

This species is monotypic.

Distribution. From Colombia (W periphery of the Amazon Basin), S by the Amazonian slope of Andes in E Ecuador and Peru to N Bolivia (La Paz and Cochabamba departments), and Brazil (along Peruvian border, Acre State). View Figure

Descriptive notes. Head-body 84-93 mm (tailless), ear 21-22 mm, hindfoot 14-21 mm, forearm 56-1-61-6 mm; weight 41-59 g. Greatest lengths of skulls are 27-9-29-9 mm. Along with the Arata-Thomas Yellowshouldered Bat (S. aratathomasi ), the Greater Yellow-shouldered Bat are the largest known species of Sturnira . Fur is yellowish or golden brown, but in Bolivia,it can be darker or grayish,similar to the Arata-Thomas Yellow-shouldered Bat that is commonly dark grayish. Hairs have white bases, light grayish brown epibasal bands (c.2: 5 mm), light buff subterminal bands (3-5 mm), and dark brown terminal bands (c.0-5 mm). This banding gives the appearance of a conspicuously mottled fur on shoulders, back, and rump. Ventral pelage is pale yellow, brown, or gray and paler than dorsal pelage. Hairs are tricolored, with pale tips longer than tips of dorsal hairs. Banding patterns of hairs are less evident in subadults. Proximal two-thirds of forearm is heavily furred on dorsal and ventral surfaces. Tibia is also heavily furred dorsally, with hairs 3-5 mm long. Tail is absent, and uropatagium is greatly reduced, although it is fringed with long hairs (c.5-8 mm). Calcar is shorter than foot, which is large and dorsally covered with hair. Wing membranes, noseleaf, and ears are dark brown or blackish brown. Ears become darker toward medial and distal margins. Presence of epaulettes (stained and stiffed shoulder hairs)is variable in both sexes but generally prominent in males. In Colombia, epaulettes are conspicuous and vary in brightness in some males, while hairs on others are conspicuously frosted but indistinguishable from surrounding fur. In females, epaulette color can vary from ocherous to orange, with soft and less extensive hairs than in males. Variation in shoulder color can be correlated with reproductive state or breeding season. The Greater Yellow-shouldered Bat most closely resembles the Highland Yellow-shouldered Bat (S. ludovici ) in general shape and proportions, but it is much larger and broader, with broad zygomatic breadth. Morphometric analyses revealed significant secondary sexual dimorphism;it is not evident in external characters, but in alar, cranial, and dental characters, males are larger than females. Males have considerably longer canines and longer length through upper and lower canines, which results in a wider muzzle in males. These differences could have a functional significance; males might be able to consume food items of greater size and hardness. Teeth are relatively small (only slightly larger than in largest specimen of the Highland Yellow-shouldered Bat). Lingual cusps on M and M, are poorly defined, and lower incisors are trilobed, with middle lobe slightly lower than lateral lobes. Upper tooth rows arch symmetrical, and upper molars are flatter, with broader occlusal surface than in the Highland Yellow-shouldered Bat and with low, rounded labial and lingual cusps. Chromosomal complement has 2n = 30 and FN = 56.

Habitat. Lowland tropical forest at elevations of 300 m orless in localities proximal to the Amazon Basin in Colombia, Ecuador, and Peru and pre-montane and montane forest in Peru and Bolivia at elevations of 200-2300 m ( Ecuador, Peru, and Bolivia) and 100-915 m ( Colombia). In Brazil, the Greater Yellow-shouldered Bat occurs in dense, hilly, primary forest. It has also been found in secondary forests, clearings surrounded by tropical forest, farms, and fruit crops.

Food and Feeding. A study in Ecuador found seeds and pulp of Anthurium (Araceae) , Marcgravia helverseniana ( Marcgraviaceae ) and Piper ( Piperaceae ) in feces of Greater Yellow-shouldered Bats. It has been suggested that it could be in an insectivorous and nectarivorous secondary feeding guild.

Breeding. In Peru, a pregnant Greater Yellow-shouldered Bat was found in March and several lactating females in May-June. Actively reproductive males, with enlarged testes, have been caught in May and July in Peru. In Colombia, there is a record of a pregnant female with one fetus (crown-rump length of 14 mm) in November and postlactating females with enlarged mammae surrounded by bare areas of skin in May. No records of reproductive males in Colombia have been published. In Bolivia, there are only records of males with enlarged testes (greater than 6 mm in length) in July. Data from the most extensive collection of bats in Ecuador revealed records of pregnant females in February, April, and November; lactating females in March, December, and October; and reproductive males in January and May. In Brazil, lactating, postlactating, and early pregnant females were recorded in July. This rather scarce published information suggests that the Greater Yellow-shouldered Bat exhibits a bimodal polyestrous pattern. It has been suggested that parturition can occur in local dry and wet seasons.

Activity patterns. The Greater Yellow-shouldered Bat is nocturnal. It is expected to mainly forage in understories where it finds its food resources and to roost in tree cavities, bases of palm fronds, caves, tunnels, and other man-made structures.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The IUCN Red Lust.

Bibliography. Aguirre (2007), Anderson et al. (1982), Arguero et al. (2012), Baker (1979), Bernard et al. (2011), Gardner (1976), Graham (1983), Hice et al. (2004), Nogueira et al. (1999), Peterson & Tamsitt (1968), Tamsitt & Hauser (1985), Tamsitt & Valdivieso (1986), Tamsitt et al. (1986), de la Torre (1966), Villalobos & Valerio (2002).














Sturnira magna

Don E. Wilson & Russell A. Mittermeier 2019

Sturnira magna

de la Torre 1966