Sphaeronycteris toxophyllum Peters 1882

215.

Visored Bat

Sphaeronycteris toxophyllum

French: Sténoderme a visiére / German: Schirmfledermaus / Spanish: Stenodermo de visera

Taxonomy. Sphaeronycteris toxophyllum Peters, 1882,

“America tropicalis.” Restricted by A. Cabrera in 1958 to Pebas, Loreto, northern Peru.

Morphology of S. toxophyllum is very distinct, and its taxonomy has remained stable. Although its specific epithet has been associated to other Stenodermatini genera, the original combination is accepted. Monotypic.

Distribution. N South America from N & E Colombia and Venezuela to W Brazil, E Ecuador, E Peru, and N Bolivia.

Descriptive notes. Head-body 58-85 mm (tailless), ear 14-17 mm, hindfoot 11-17 mm, forearm 36-41 mm; weight 11-21 g. The Visored Bat is a small fruit-eating and sexually dimorphic species. Dorsal fur is reddish brown to deep brown, with paler venter that can be buff to pale grayish to whitish. Dorsal hair has four bands: narrow basal whitish band, broader reddish-brown band, another broader white to buff band, and terminal narrow band thatis reddish brown to light brown. There are four white spots arranged in two pairs: one on each shoulder where wing meets body, similar to those in the closely related Wrinkle-faced Bat (Centurio senex), and another more diffuse pairjust below base of ear. Ears are small and slightly elongated, and eyes are large and golden brown. Males have striking sexual dimorphic,visor-like, fleshy appendage, soft to the touch, that extends forward from forehead and arises from just above inner corner of eyes. This visor is approximately square, with rounded corners. Males also have fold of skin in the neck than can be extended at will over part of the face, similar to that in Wrinkle-faced Bat. Rostrum is very short. Face is naked except for top of visor that is covered with sparse short hairs. There is no discernible noseleaf on males because it is fused with underside of visor. Females have no visor, but they do have a discernible noseleaf thatis short and rounded. Uropatagium is narrow and furry, with fringe of hairs that extends beyond its edge. Dental formulais12/2,C1/1,P 2/2, M 3/3 (x2) = 32. Cranium is relatively large and globose, with short rostrum. Anterior margin of orbit consists of conspicuously thin plate, and zygomatic arches expand laterally. Chromosomal complement has 2n = 28 and FN = 52. X-chromosome is subtelocentric, and Y-chromosome is submetacentric.

Habitat. Variety of tropical habitats including tropical deciduous forests, Amazon rainforests, cloud forests, secondary forests, gardens, and even pastures from sea level up to elevations of ¢. 3000 m.

Food and Feeding. The Visored Bat feeds on fruit. Its taxonomic affinity to the Wrinklefaced Bat and other shortfaced stenodermatines suggests that it feeds on soft, fleshy fruits, butit also might be able to crush hard food items such as seeds.

Breeding. Female Visored Bats have one embryo per pregnancy. There are two birth peaks, one at beginning of rainy season and one toward the end of rainy season. Pregnant and lactating females have been found in April and September—October.

Activity patterns. Most Visored Bats have been caught in mist nets well after dusk. Two bats were found in the morning roosting on a small (2m tall) ornamental Ficus (Moraceae) tree in Iquitos, Peru. One specimen was found in a cavity in the ground, and two others were found in a building housing an electrical plant.

Movements, Home range and Social organization. Visored Bats are usually caught singly or in pairs, often a male and a female. It has been suggested that it is an elevational migrant. It is rarely common, but at one locality in south-eastern Peru, more than 20 individuals were netted near streams associated to bamboo thickets.

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

Bibliography. Angulo & Diaz (2004), Angulo et al. (2008), Cabrera (1958), Gardner (2008f), Rodriguez-Posada & Cardenas-Gonzalez (2012).