Saccopteryx leptura (Schreber, 1774)

Bonaccorso, Frank, 2019, Emballonuridae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 350-373 : 372

51 . Lesser Sac-winged Bat

Saccopteryx leptura

French: Saccoptère commun / German: Kleine Sackflügelfledermaus / Spanish: Sacóptero menor

Other common names: Brown White-lined Bat, Lesser White-lined Bat

Taxonomy. Vespertilio lepturus Schreber, 1774 ,

“ Surinam [= Suriname ].”

This species is monotypic.

Distribution. From S Mexico (Chiapas State) S throughout Central America to N & E Colombia, E Ecuador, E Peru, N Bolivia, and E to E & SE Brazil (S to Sâo Paulo State), and S throughout W Colombia to Ecuador; also on Margarita I (Venezuela) and Trinidad and Tobago Is.

Descriptive notes. Head-body 38-51 mm, tail 9—19 mm, ear 12-15 mm, hindfoot 6-10 mm, forearm 37-43 mm; weight 3-6 g. Female Lesser Sac-winged Bats are slightly larger than males. Dorsal fur is uniformly dark brown, with two buff-colored longitudinal wavy stripes on either side of median of back that extend from shoulders onto rump. Venter is significantly paler brown. Wing sacs containing odiferous glands occur next to forearm, close to elbow, and open on dorsal surface of antebrachial membrane. Wing sacs are more developed in males. Skull has well-developed postorbital processes. Premaxillae are usually free and always incomplete with distinct suture boundaries.

Habitat. Lowland deciduous and evergreen forests from sea level to 914 m but most commonly below 100 m. In Mexico, the Lesser Sac-winged Bat also occurs in secondary forests, croplands, and grasslands.

Food and Feeding. Lesser Sac-winged Bats feed on aerial insects including moths. They occasionally forage over streams, but closed canopy appears to be preferred foraging habitat. Roosting groups defend foraging territories of 0-1—1-8 ha.

Breeding. At least in parts of the distribution, Lesser Sac-winged Bats are polyestrous. In Costa Rica, first birth peak of the year occurs in May near onset of rainy season, and a second birth peak occurs in October-November. In Trinidad, there is one birth peak per year in May. Females carry their young for 10-15 days, after which young can fly, but they continue to nurse until c.2-5 months of age. Females can reproduce at 12-18 months of age.

Activity patterns. Lesser Sac-winged Bats are crepuscular. Roost sites are often found on exposed trunks of a large variety of tree species in riparian habitats. Other roosts include undersides of large-leafed plants (e.g. banana and coconut) and in abandoned buildings. Groups of Lesser Sac-winged Bats emerge in late afternoon daylight and forage together in forest canopies until after complete darkness when a group might ascend to forage in forest canopies. Individuals fly repeated back and forth loops within defined feeding areas. During the day, individuals remain alert in roosts and maintain high resting metabolic rates. Echolocation prey search calls have frequencies of C.45—95 kHz, with maximum energy of c.55—60 kHz.

Movements, Home range and Social organization. Roosting groups of Lesser Sacwinged Bats have 1—9 individuals, usually representing a pair of adults and their offspring. Social groups are somewhat fluid, with individuals entering and leaving a given group. Densities range from 2-5 ind/ha in Costa Rica to 17-6 ind/ha in Trinidad; biomass estimates are 14—97 g/ha in these two countries. Males defend individual females during breeding when they occur as monogamous pairs. A variety of audible chirps are used for communication at roosts.

Status and Conservation. Classified as Least Concern on The IUCNRed List. The Lesser Sac-winged Bat has a large distribution and presumably large and stable overall population, and it occupies a wide range of habitats. It occurs in many protected areas. In Mexico, it receives special protection. Forest loss from conversion to pasture and agriculture is the primary threat, particularly in the Brazil.

Bibliography. Bradbury &Vehrencamp (1976a, 1977 a, 1977b), Carter et al. (1981), Cruz-Parrado et al. (2018), Eisenberg (1989), Emmons & Feer (1997), Garbino (2011), Jones & Hood (1993), Koopman (1993), McNab (1982,1989), Reid (2009), Webster & Jones (1984c), Yancey et al. (1998).

Figures

On following pages: 40. Lesser Ghost Bat (Diclidurus scutatus); 41. Isabelline Ghost Bat (Diclidurus isabella); 42. Lesser Dog-like Bat (Peropteryx macrotis); 43. Greater Dog-like Bat (Peropteryx kappleri); 44. Trinidad Dog-like Bat (Peropteryx trinitatis); 45. White-winged Dog-like Bat (Peropteryx leucoptera); 46. Pale-winged Dog-like Bat (Peropteryx pallidoptera); 47. Thomas's Shaggy Bat (Centronycteris centrali); 48. Common Shaggy Bat (Centronycteris maximiliani); 49. Proboscis Bat (Rhynchonycteris naso); 50. Greater Sac-winged Bat (Saccopteryx bilineata}; 51. Lesser Sac-winged Bat (Saccopteryx leptura); 52. rosted Sac-winged Bat (Saccopteryx canescens); 53. Antioquian Sac-winged Bat (Saccopteryx antioquensis); 54. Amazonian Sac-winged Bat (Saccopteryx gymnura).

Distribution. From S Mexico (Chiapas State) S throughout Central America to N & E Colombia, E Ecuador, E Peru, N Bolivia, and E to E & SE Brazil (S to Sâo Paulo State), and S throughout W Colombia to Ecuador; also on Margarita I (Venezuela) and Trinidad and Tobago Is.