Eonycteris

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Eonycteris
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Chiroptera
Family: Pteropodidae
Subfamily: Macroglossinae
Genus: Eonycteris
Species: E. spelaea & E. major

Eonycteris is a genus of fruit bats consisting of E. spelaea and E. major found in Asia. They form colonies in caves or hollow trees of fewer than a hundred to tens of thousands, and contribute to pollination of various crops in plantations [1].

Contents

[edit] Eonycteris spelaea

Cave nectar bat [2].

[edit] Distribution

E. spelaea were mist-netted at eight locations, Sungai Dusun (n = 4), Sungai Enam (n = 1), Wang Pinang (n = 11) and Taleban (n = 1) on the Southeast Asia mainland and Gunung Gading (n = 1), Kubah (n = 1), Kampong Melayu Rayu (n = 2) and Gunung Silam (n = 2) in Borneo. Its range includes India, China, Southeast Asia, Philippines, Sumatra, Java and Borneo. It had been previously recorded from Gomantong, Sukau, Segama and Madai in Sabah; Niah, Sungai Tinjar and Kuching in Sarawak; and Sungai Tengah and Kutai in Kalimantan [3].

[edit] Biology and ecology

This species were caught near fruiting Ficus in forest fringe in Wang Pinang and in regenerated habitat at Gunong Gading National Park. The regenerated area was used for agriculture and contained banana plots. There were ten males, ten females and three could not be sexed. Sixteen were adults, four subadults, two immatures and one was not aged before release. Females (B0679 and B0683) banded in March 1997 at Wang Pinang were lactating. At the same date a male (B0684) from Wang Pinang had enlarged testes during that period. A female (B0762) from Sungai Dusun was in postlactation in May 1997. The presence of subadults and immatures between March and May at Wang Pinang, Sungai Dusun and Taleban suggesting of births occurred a few months before.

In Batu Caves, in Peninsular Malaysia. Beck and Lim[4] observed that there was no evidence that E. spelaea had a regular reproductive pattern. More than 50% of the adult females were pregnant or lactating every month during the study period 1966 to 1968. Peak pregnancy rates occurred in May - June and October - November in 1966 and in April - May and September 1967. Parturition and lactation periods occurred during heavy and low rainfalls. High rates of parturition were recorded in June and November 1966 and June and September 1967. The weaning period finished approximately eight weeks after birth. Gestation period was estimated between 6 to 6.5 months in Malaysia [4] and three to four months in India [5]. By using four months gestation, Heideman [6] projected that parturition in Negros occurred in January, May, July, September, November and December. In north-east India, Bhat et al. [5] estimated that E. spelaea lactate for five to eight weeks. On Leyte Island, the Philippines, females carrying neonates or juveniles suggested a seasonal and synchronous pattern of reproduction [6]. Kitchener et al. [7] reported that two pregnant females and 60% juveniles were collected on Lombok Island in October. In May, seven individuals were pregnant and one was a juvenile. Their data indicated that birthings for the species occurred before the on-set of the rainy season in October and most immatures from the recent parturient season were flying.

E. spelaea usually roosts in large colonies in caves [3]. The bat flies long distances in search of flowering trees; feeds on pollen and nectar [8]. Ecologically, the cave nectar bat is found to be a major pollinator of many forest trees including the commercially important durians (Durio) in Malaysia [8]; [3]. An adult female (B0213; forearm length 67.0 mm, weight 53.5 g) from Gading was netted with a Ficus species fruit weighing 13 g.

[edit] External measurements

14 samples; FA = 66.94±1.71, TL = 13.53±3.55, EL = 16.42±1.55, HD = 36.70±1.41(10), TB = 30.25±1.21, WT = 51.46±7.52, HB = 98.24±7.38(10), WS = 446 (1), HF = 14.24±1.77 (9), D5 = 75.73±2.43 (11).

[edit] Eonycteris major

Greater nectar bat [9]

[edit] Distribution

E. major were mist-netted in Tawau (n = 7 including a recapture) and Poring (n = 1) in Sabah. These represent additional distribution record for the species in Sabah. Its range is limited and includes Luzon to Maripipi in the Philippines and scattered parts of Borneo including Tauran and Ranau in Sabah; Bau, Kuching and Bintulu in Sarawak [10] [3].

[edit] Biology and ecology

All individuals captured were adult females except B0348, which was a subadult. In Tawau, one female was pregnant and another was lactating in July 1996. A subadult female was netted in the same site which indicated recent parturition.

All E. major were mist-netted in sites associated with flowering banana plants (Musa species) found on the edge between primary forest and open or secondary habitats. An individual (B0314) was netted and banded at 2205 hours on 5 July 1996 was recaptured in another net the following night at 1850 hours about 30 m away. This may suggest of stable food resources at the edge or lack of feeding sites elsewhere. The area surrounding Tawau Park is covered oil palm plantations or disturbed habitats. This species usually roosts in caves and hollow trees, but there is little other information on the ecology of this species [3].

[edit] External measurements

FA = 80.48±9.94, TL = 19.52±2.71, EL = 19.38±1.09, TB = 34.82±3.68, WT = 83.20±17.79, D5 = 97.29 (1); 5 samples. At Tawau Hills in Sabah, a female was pregnant (B0315) with FA 80.5 mm and WT 103 g, the other female B0317 with FA 81.24 mm and WT 94 g while another was lactating female B0314 with FA 78.46 mm and WT 87.50 g. The measurements are consistent with those reported by [3].

[edit] References

  1. ^ Jansa, S. 1999. "Eonycteris spelaea", Animal Diversity Web. retrieved July 17, 2006
  2. ^ Dobson, 1871
  3. ^ a b c d e f Payne, J., C.M. Francis and K. Phillipps. (1985) A field guide to the mammals of Borneo. The Sabah Society, Kota Kinabalu, Sabah.
  4. ^ a b Beck, A.J. and B.L. Lim (1973) Reproductive biology of Eonycteris spelaea in West Malaysia. Acta Trop. 30(3):251-260
  5. ^ a b Bhat, H.R., M.A. Sreenivasan, and P.G. Jacobs. (1980) Breeding cycle of Eonycteris spelaea (Dobson, 1871)(Chiroptera, Pteropodidae, Macroglossinae) in India. Mammalia 44(3):343-347
  6. ^ a b Heaney, L.R. and Heideman, P.D. (1987) Philippine fruit bats, endangered and extinct. Bats 5: 3-5.
  7. ^ Tidemann, C.R., Kitchener, D.J., Zann, R.A. and Thornton (1990), Recolonisation of the Krakatau Islands and adjacent areas of West Java, Indonesia, by bats (Chiroptera) 1883-1986, I.W.B.
  8. ^ a b Start, A. N., AND A. G. Marshall, (1976) Nectarivorous bats as pollinators of trees in West Malaysia, Academic Press, London
  9. ^ . Andersen, K, (1910) Ten new fruit-bats of the genera Nyctimene, Cynopterus, and Eonycteris, Ann. Mag. Nat. Hist., ser. 8, 6: 621-625
  10. ^ Mickleburgh, S.P., Hutson, A.M., & Racey, P.A. (1992) Old world fruit bats: an action plan for their conservation. I. U. C. N/S. S. C., Gland, Switzerland