Sturnira bidens
Creators: name: Wilson, Don E.
name: Mittermeier, Russell A.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Phyllostomidae
Sturnira
Sturnira bidens

description: 119. Bidentate Yellow-shouldered Bat <i>Sturnira bidens</i> <b>French:</b> Sturnire bidentée / <b>German:</b> Gelbschulterfledermaus / <b>Spanish:</b> Sturniro bidente <b>Taxonomy.</b> Corvira bidens Thomas, 1915, “Bacza, Upper Coca River, Oriente [= Napo] of N. Ecuador. Alt. 6500’ [= 1981 m].” The taxon bidens was the basis for a new genus, Corvira, which was later included as a subgenus of Sturnira. Recent phylogenetic analyses indicate that S. bidens is not closely related to S. nana, so if the name Corvira is used as a generic name again,it should only include S. bidens. Monotypic. <b>Distribution.</b> Andean regions of W Venezuela, Colombia, Ecuador, and Peru. <b>Descriptive notes.</b> Head-body 62-67 mm (tailless), ear 13-17 mm, hindfoot 14-16 mm, forearm 39-7-43-3 mm; weight 14-21 g. The Bidentate Yellow-shouldered Bat 1s medium-sized. Upperparts are variable, from pale brown to brown or dark grayish brown. Shoulder patches are almost indistinguishable. Underparts are dark brown. Pelage is soft and woolly, with long (7-8 mm) dorsal hairs having 3-4 bands; almost whitish basal band can be absent in populations near Merida (north-western Venezuela). Tail membrane is very short and densely furred. Forearm, femur, and adjacent parts of wings are sparsely haired, but legs and feet are densely furred. Skull is relatively long, narrow, and anteriorly sloping, with weak or incomplete zygomatic arches. There is a single pair of lower incisors (I) and small molars and premolars separated by narrow gaps. Dental formulais12/1,C1/1,P 2/2, M 3/3 (x2) = 30. Chromosomal complement has 2n = 30 and FN = 56. It is similar to most known karyotypes of species of Sturnira in having an acrocentric Y-chromosome. <b>Habitat.</b> Andean forests at elevations of 1700-3000 m (mostly above 2200 m). The Bidentate Yellow-shouldered Bat is found in evergreen and cloud forests, although it can be netted on forest edges and secondary forests. <b>Food and Feeding.</b> Being a highland specialist, diet of the Bidentate Yellow-shouldered Bat is comparatively less diverse than other species with broader elevational ranges. It includes at least 17 plant species in its diet, mostly fruits of Solanum (Solanaceae). Other fruits include Vismia (Hypericaceae), Ficus (Moraceae), Piper (Piperaceae), and Anthurium (Araceae). Lack of insects in several dietary studies might indicate that it is strictly frugivorous, which would be reinforced by its sedentary habits. <b>Breeding.</b> In central Peru, pregnant Bidentate Yellow-shouldered Bats were recorded in August. More extensive data from Merida conform to bimodal polyestry. Pregnancy and lactation should occur through the year, with at least two peaks of pregnancy: February-March (end of dry season) and June-July (short dry season). This means parturition occurs right before rainy seasons begin. <b>Activity patterns.</b> Bidentate Yellow-shouldered Bats are nocturnal. Activity peaks in first two hours after dusk, with lower peaks throughout the night. Only known roost is a cave in Colombia. <b>Movements, Home range and Social organization.</b> High recapture rate of Bidentate Yellow-shouldered Bats at the Cordillera de Mérida could indicate they have small and rather fixed home ranges (or foraging areas). <b>Status and Conservation.</b> Classified as Least Concern on The IUCN Red List. The Bidentate Yellow-shouldered Bat has a wide distribution and presumably large populations. <b>Bibliography.</b> Baker (1979), Castano et al. (2018), Gardner (2008g), Gardner &amp; O'Neill (1969), Molinari &amp; Soriano (1987), Pacheco &amp; Patterson (1991), Velazco &amp; Patterson (2013).
description: Published as part of <i>Don E. Wilson &amp; Russell A. Mittermeier, 2019, Phyllostomidae, pp. 444-583 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions</i> on page 543, DOI: 10.5281/zenodo.6458594