Rhynchonycteris naso, Wied-Neuwied, 1820

Bonaccorso, Frank, 2019, Emballonuridae, Handbook of the Mammals of the World – Volume 9 Bats, Barcelona: Lynx Edicions, pp. 350-373 : 370-371

49 . Proboscis Bat

Rhynchonycteris naso

French: Nasin des rivières I German: Nasenfledermaus / Spanish: Murciélago narigón

Other common names: Brazilian Long-nosed Bat, Long-nosed Proboscis Bat, River Bat, Sharp-nosed Bat

Taxonomy. Vespertilio naso Wied-Neuwied, 1820 ,

“ Mucuri.” Restricted by F. D. de Avila- Pires in 1965 to “Vcinity of Morro d’Arara, Rio Mucuri , State of Bahia, Brazil.”

This species is monotypic.

Distribution. From S Mexico (Veracruz and Oaxaca) S throughout CentraAmerica to Colombia, E to C & E Brazil, and S to E Ecuador, E Peru, and N & NE Bolivia and also on Trinidad I.

Descriptive notes. Head-body 36-48 mm, tail 11-17 mm, ear 11-14 mm, hindfoot 6-8 mm, forearm 36-40 mm; weight 3-6 g. Long, fluffy dorsal fur of the Proboscis Bat is grizzled gray-brown, with yellow tones and two faint, wavy, cream-colored stripes extend from shoulders to rump. Venter is pale yellow or grayish. Nose is long and projects well beyond lower lip. Flight membranes and facial skin are black. Tufts of whitish fur on forearms are diagnostic. Wing sacs are absent. Calcar is about three times as long as feet, and uropatagium is longer than legs. Dental formula is 11/3, C 1/1, P 2/2, M 3/3 (x2) = 32.

Habitat. Almost always associated with water and wedands (streams, rivers, mangroves, and lakes) near multi-strata evergreen forests, semideciduous forests, dry forests, secondary forests, croplands, or pastures from sea level to elevations of c.1500 m (generally most common below 500 m).

Food and Feeding. Proboscis Bats are aerial insectivores and usually forage within 3 m of surface of slow moving, shallow water. Diet includes small dipterans including mosquitoes.

Breeding. Proboscis Bats are monoestrous; single young are bom once a year in early wet season.

Activity patterns. Proboscis Bats are crepuscular, and their foraging flights usually begin well before sunset and continue into darkness. They roost on tree trunks, exposed logs, boulders, and steep banks; under bridges; and in tree cavities, always near or direcdy above water. Roosting individuals usually form a single vertical line. Color pattern of the Proboscis Bat makes it extremely cryptic when it roosts on tree bark. Echolocation call contains a F component at c.100 kHz.

Movements, Home range and Social organization. Proboscis Bats usually roost in small, single-species colonies of c.10-24 individuals, but groups of up to 100 individuals have been noted. When roosting, they are often aligned in vertical rows with individual spacing of c.20-40 mm. Several males occur in a roosting group, and there appears to be no harem formation or defense. If disturbed, a group flies together to an alternate roost. At times, all group members rock back and forth like leaves blowing in the wind. Spiders frequently prey on Proboscis Bats. The orb-web spider Argiope submaronica has been observed to feed on adult Proboscis Bats. In Costa Rica, a Proboscis Bat near a roost under eaves of a building was entangled in the center of a web; it was wrapped in silk and fed upon by the spider. The orb-weaver Nephila clavipes also was observed capturing and feeding on Proboscis Bats in Peru.

Status and Conservation. Classified as Least Concern on 77 zr IUCN Red List. The Proboscis Bat has a large distribution and presumably large and stable overall population, and it is common in areas with suitable wetland habitats. It can be locally common and found in many protected areas in Mexico, Central America, and South America. In Mexico, it is provided special protection.

Bibliography. Avila-Pires (1965), Dalquest (1957), Eisenberg (1989), Emmons & Feer (1997), Goodwin & Greenhall (1961), Husson (1978), Nyffeler & Knörnschild (2013), Timm & Losilla (2007).

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 (Veracruz and Oaxaca) S throughout CentraAmerica to Colombia, E to C & E Brazil, and S to E Ecuador, E Peru, and N & NE Bolivia and also on Trinidad I.