120.

Lesser Yellow-shouldered Bat

Sturnira nana

French: Sturnire naine / German: Kleine Gelbschulterfledermaus / Spanish: Sturniro enano

Taxonomy. Sturnira nana Gardner & O’Neill, 1971,

“Huanhuachayo (12°44’S, 73°47'W), ca. 1,660 meters, Departamento de Ayacucho, Pera.”

Sturnira nana was originally associated with S. bidens in the subgenus Corvira, but phylogenetic analyses shown they are not close relatives. Monotypic.

Distribution. Known only from SE Ecuador (Cordillera del Condor, Zamora Chinchipe Province) and type locality in SC Peru.

Descriptive notes. Head—body 47-50 mm (tailless), ear 13-15 mm, hindfoot 9-15 mm, forearm 32-6-35-7 mm; weight 10-12 g. The Lesser Yellow-shouldered Batis the smallest species of Sturnira. Upperparts are dark grayish brown. Shoulder glands are absent. Dorsal hairs are long (7-8 mm), with 3—4 bands: almost white basal band, brown medial band, then light silvery brown band, and brownish narrow tips. Underparts are slightly lighter because hairs lack brownish tips. Noseleaf is long and narrow. Forearm, legs, feet, adjacent part of the wings, and short tail membrane are sparsely haired. Skull is relatively long, narrow, and anteriorly sloping, with weak or incomplete zygomatic arches. There are two pairs of lower incisors; I, are broad and trilobed; I, are minute (or absent) and hardly distinct in live individuals; I' have broader tips compared with the Bidentate Yellow-shouldered Bat (S. bidens), and they are in contactat tips; and small molars and premolars are separated by narrow gaps. Dental formula for all species of Sturnira except the Bidentate Yellow-shouldered Batis12/1-2,C1/1,P 2/2, M 3/3 (x2) = 30-32. Chromosomal complement has 2n = 30 and FN = 46, with 14 biarmed autosomal chromosomes. X-chromosome is subtelocentric, and Y-chromosome is acrocentric.

Habitat. Only known from three Andean localities in Peru and Ecuador within a narrow elevational band of 1250-1670 m. Lesser Yellow-shouldered Bats were netted in low montane forests and at edges of clearings on eastern slope of the Andes.

Food and Feeding. Diet of the Lesser Yellow-shouldered Bat is presumably similar to other small species of Sturnira, especially those from montane forests. It might depend on fruits of Solanum (Solanaceae) but also include Vismia (Hypericaceae), Ficus (Moraceae), Piper (Piperaceae), and Anthurium (Araceae) species.

Breeding. No information.

Activity patterns. Lesser Yellow-shouldered Bats are nocturnal.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Endangered on The IUCN Red List. Known area of occupancy of the Lesser Yellow-shouldered Bat is less than 500 km? at two locations (south-eastern Ecuador and central Peru). This small area is severely fragmented and threatened by habitat conversion (small-scale agriculture and wood logging).

Bibliography. Boada (2011), Gardner (1977a, 2008g), Gardner & O'Neill (1971), Pacheco & Patterson (1991), Regalado & Albuja (2012), Velazco & Patterson (2013).