Pteropodidae
Author
Don E. Wilson
Author
Russell A. Mittermeier
text
2019
2019-10-31
Lynx Edicions
Barcelona
Handbook of the Mammals of the World – Volume 9 Bats
16
162
book chapter
88683
10.5281/zenodo.6448815
bbbf94d9-a910-4cda-97df-7eca124163ed
978-84-16728-19-0
6448815
41.
Geoffroy’s Rousette
Rousettus amplexicaudatus
French:
Roussette de Geoffroy
/
German:
Geoffroy-Flughund
/
Spanish:
Rosetus de Geoffroy
Other common names:
Common Rousette
Taxonomy.
Pteropus amplexicaudatus E. Geoffroy Saint-Hilaire, 1810
,
“L’ile de Timor [= Timor: Island],” Lesser Sunda Islands.
Subspecies of
R. amplexicaudatus
differ mainly in size, with
amplexicaudatus
being the largest and
brachyotis
the smallest. The
form hedigeri
from Bougainville Island (
Solomon Islands
) is considered a synonym of
brachyotis
; the
form minor
from Java is considered a synonym of infumatus. Taxonomic status ofthe recently described R. tangkokoensis by H. J. Lengkong and colleagues in 2016 from northern
Sulawesi
, similar to
R. amplexicaudatus
, needs additional investigation. Three subspecies recognized.
Subspecies and Distribution.
R.a.amplexicaudatusE.GeoffroySaint-Hilaire,1810—mainlandSEAsia(C&SEMyan-mar,SCChinainYunnan,NLaos,andNVietnamStoMalayPeninsula),Philippines,MentawaiIs(NorthPagai),EngganoI,Borneo,Moluccas,ELesserSundaIs(Flores,Sawu,Roti,Timor,andKisar),TanimbarIs,NewGuinea(includingWaigeo,Batanta,Salawati,andYapenIs),andLouisiadeArchipelago(SideiaI);SulawesianandnearbyIspopulations(Sangihe,Thulandang,Talisei,Lembeh,Batudaka,andPeleng)aretentativelyassignedtothissubspecies.
R.a.brachyotisDobson,1877—AdmiraltyIs(Manus),BagabagI,BismarckArchipelago(Mussau,Emirau,NewHanover,NewIreland,Dyaul,Tabar,Lihir,DukeofYork,andNewBritainIs),andSolomonIs(Buka,Bougainville,Fauro,Choiseul,VellaLavel-la,Kolombangara,NewGeorgia,Vangunu,SantaIsabel,Guadalcanal,NggelaSule,Malaita,andSanCristobal).
R. a. infumatus J. E. Gray, 1870
—
Sumatra
,
Java
, and W Lesser Sunda Is (
Bali
, Nusa Penida, and Lombok; possibly also on Alor).
Descriptive notes.
Head—body
128-154 mm
, tail
13-24 mm
, ear 16-
5-24 mm
, hindfoot
19-21 mm
, forearm
70-92 mm
; weight
64-106 g
. Males are always larger on average than females. Geoffroy’s Rousette is similar to Leschenault’s Rousette (
R. leschenaultii
), distinguished by subcircular (as opposed to elliptical) occlusal outline of M,, narrower ears, and proportionally more slender and shorter rostrum. Ears are narrow, tips are not attenuated, and antitragus is small and round. Fur coloris similar to that of other species of
Rousettus
: generally brown and grayish drab on chest, breast, and belly. It has been suggested that darker hue might be useful to distinguish Geoffroy’s Rousette from other eastern species of
Rousettus
. Head, back, and rump range from dark brown to dark olive or sepia-brown; nape is wood-brown to greenish brown; sides of neck and fore neck are more or less suffused with wood-brown or tawny olive in males and greenish brown in females. Distinct band of dorsal fur, 15-35-
5 mm
wide, occurs between both plagiopatagium insertions. Furis rather short and sparse. Neck region is almost naked. Uropatagium and tibia are almost bare. Adults of both sexes can have two bright-colored and bristly hair tufts, one at either side of neck; these tufts occur especially in older specimens and are often absent, without geographical regularity. Wing membranes are dark brown but are nearly translucent over bones giving appearance of white stripes. Claw is present on index finger. Palatal ridges are variable depending on subspecies: 3+4+1,4+3+1,0or4+4 +1 (less commonly). Dental formula for all species of Rousettusis12/2, C1/1,P 3/3, M 2/3 (x2) = 34. Dentition is conservative in tooth number and structure of dental pieces. There is a tendency in Geoffroy’s Rousette for reduction of interspace between C' and P?%P! in some individuals is closely wedged between those two teeth (absent in a few individuals); this characteristic is variable, without correlation to geography. Premolars and molars vary in size but are similar to those of Leschenault’s Rousette. Chromosomal complement has 2n = 36 and FN = 68.
Habitat.
Primary and secondary forests, mixed agricultural land (orchard), and open areas, from sea level up to elevations of ¢.
2200 m
. Geoftroy’s Rousette also occurs in residential areas up to elevations of ¢.
500 m
.
Food and Feeding.
Geoffroy’s Rousette is frugivorous but also eats nectar. It often feeds on overripe fruits, minimizing their damage in commercial orchards. On Panay Island (
Philippines
), diets included native and exotic fruits from at least 14 genera and eleven families.
Ficus
was very important on Panay Island, with eleven species included in diets. Flowers from
Erythrina (Fabaceae)
and
Barringtonia (Lecythidaceae)
are used.
Breeding.
On Negros Island (
Philippines
), multiparous Geoffroy’s Rousettes gave birth in March-April and usually August-September, a pattern of seasonal bimodal polyestry. Exact timing of these birth periods probably varies from year to year, but births coincide with beginning of dry season and early wet season. Females were lactating and pregnant when captured in April-May, indicating that most females have young in both birthing periods and postpartum estrus. Females become pregnant in their first year oflife; first births occurred in broad peak from June to late August. Gestation is ¢.150 days, and lactation lasts ¢.60 days. Crown—rump length of neonates is ¢.
47 mm
. A similar reproductive pattern was observed in New Guinean populations, with females producing two litters of one young annually. Geoffroy’s Rousettes might have a harem-type of mating system; adult males are less abundant than females.
Activity patterns.
On Mindanao, Geoffroy’s Rousette roosted in caves with large openings and close to water, and it might use rock crevices and old tombs. It is docile when handled, rarely calling or biting.
Movements, Home range and Social organization.
Geoffroy’s Rousette roosts in large colonies of2000-100,000 individuals. On the Island of Samal (
Philippines
), the world’s largest colony of Geoffroy’s Rousette was estimated at ¢.883,000 individuals in the first
100 m
of a 150 m-long cave (Monfort Cave). It often roosts in association with other fruit bats such as the Lesser Dawn Bat (
Eonycteris spelaea
). A capture-recapture study suggested that individuals have large home ranges. Geoftroy’s Rousettes regularly fly long distances (more than
20 km
/night) to forage. Genetic studies based on allozymes showed little genetic differentiation among populations in the
Philippines
, indicating high dispersal ability.
Status and Conservation.
Classified as Least Concern on The IUCN Red List. Geoffroy’s Rousette is widespread, with common and abundant populations, and seemingly not declining at a fast rate. Nevertheless,it is heavily hunted in South-east Asia, Borneo, and the
Philippines
and regarded as a pest in parts ofits distribution.
Bibliography.
Bergmans & Hill (1980), Bergmans & Rozendaal (1988), Carpenter, E.S. et al. (2014), Csorba, Rosell-Ambal & Ingle (2008), Francis (1989), Galorio & Nuneza (2014), Heaney, Dolar et al. (2010), Heaney, Walsh & Peterson (2005), Heideman & Heaney (1989), Heideman & Utzurrum (2003), Hill (1983), Hodgkison et al. (2004b), Hood et al. (1988), Lengkong etal. (2016), Rookmaaker & Bergmans (1981), Tanalgo & Hughes (2018), Tanalgo &
Tabora
(2015).