The diet of the Indian Flying Fox Pteropus giganteus (Brünnich. 1782) (Chiroptera: Pteropodidae) in Myanmar - conflicts with local people?

Sein Sein Win 1 & Khin Mya Mya 2

1 Department of Zoology, University of Kyaukse, Kyaukse Township, Mandalay Division, Myanmar

2 Department of Zoology, University of Mandalay, Mandalay, Myanmar

1 seinseinwin11@gmail.com (corresponding author), 2 dr.khinmyamya@gmail.com

 

 

doi: http://dx.doi.org/10.11609/JoTT.o4178.7568-72

 

 

Editor: Anonymity requested. Date of publication: 26 July 2015 (online & print)

 

 

Manuscript details: Ms # o4178 | Received 29 October 2014 | Final received 01 July 2015 | Finally accepted 03 July 2015

 

 

Citation: Win, S.S. & K.M. Mya (2015). The diet of the Indian Flying Fox Pteropus giganteus (Brünnich. 1782) (Chiroptera: Pteropodidae) in Myanmar - conflicts with local people? Journal of Threatened Taxa 7(9): 7568–7572; http://dx.doi.org/10.11609/JoTT.o4178.7568-72

 

 

Copyright: © Win & Mya 2015. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

 

 

Funding: None.

 

 

Competing interests: The authors declare no competing interests.

 

 

Acknowledgement: The authors are grateful to Paul Racey and Sai Aik for assistance with the preparation of this paper, which first took form during a workshop sponsored by the SEABCRU (NSF DEB # 1051363):, and to Thein Aung and Paul Bates for the photos. We thank the people of Taunginn and Htonegyi villages for their hospitality and assistance.

 

 

Abstract: The diet of Pteropus giganteus from three roosts in Mandalay Region, central Myanmar was investigated for over two years by examining feeding remains in and around two villages. It consists of 24 species of fruits, six species of flowers and three of leaves. Of these, 13 species of fruits are eaten by the local people, three of which are also marketed. Two are used in traditional medicine and one for stuffing pillows. Most dietary plants are native, mangoes are seasonally superabundant and are eaten in large numbers. Interviews revealed no evidence of conflict between bats and villagers.

 

Keywords: Diet, human-bat conflict, Pteropus.

 

 

 

 

 

Flying Foxes (Chiroptera: Pteropodidae; genus Pteropus) eat a wide range of flowers, fruits and leaves (Lobova et al. 2009; Fleming & Kress 2011). Although their protein requirements are met by digestion of pollen and leaves (Long & Racey 2007; Kunz & Ingalls 1994, respectively), the energy to power flight is provided mainly by sugars in fruits (Thomas 1984).

Some studies have suggested that the clearance of land for agriculture has led to a loss of bat’s natural foraging habitat and food plants and as a result they feed on commercial fruits (Aziz et al. in press). This often leads to conflict between bats and those who pick and market the fruits. There is little published information on the diet of flying foxes in Myanmar. The aims of this paper are to describe the diet of the commonest flying fox species in the country, P. giganteus and to assess the likelihood of its dietary habits leading to conflict with local people.

 

Methods

This study was carried out over two years (2004–2005) at Taunginn (22025.784’N & 096002.690’E) and Htonegyi villages (22026.210’N & 096002.082’E), Sintgu Township, in the northern part of Mandalay Region, Central Myanmar and on the east bank of the Ayeyarwady River (Fig. 1). There were two P.giganteus roosts in Taunginn Village and one in Htonegyi Village. The township has an area of 1409km2, the majority of which (997km2) is forested. The study sites lie in the western flat plain of Sintgu Township which is important for agriculture but is inundated during annual rains between July and September (Fig. 2). The uncultivated areas are occupied by mesophytes. Of these, mango (Mangifera indica), kapok (Bombax ceiba) and the figs Ficus rumphii and F. nervosa predominate. The climate is typical of tropical savanna. The hottest months are April and May, and the coldest months, December and January. The vegetation is diverse with many fruiting trees and many kapok trees some of which were roosting sites.

 

 

 

 

 

Information on the feeding habits of P. giganteus was obtained by collecting fruit remnants, seeds, leaves, flower parts and ejecta pellets (spat out pulp, sometimes containing seeds) dropped directly beneath all three day roosts and feeding trees. Collection of food samples was carried out for three days each month and they were examined by eye. For each specimen of fruit, flower and leaf, colour, odour and plant growth form (i.e., tree or shrub) were recorded. All the plant species were identified at the Botany Department in University of Mandalay. The availability of fruit was determined by checking trees and talking to villagers.

The location of fruit trees at the foraging sites were determined by recording the flight path of the bats, local villagers’ information and the presence of uneaten or partially eaten fruits under fruit trees. Interviews with local villagers were also carried out to obtain additional information on the food resources and foraging habits of P. giganteus. Both male and female villagers were asked a series of questions about the bats: how long the roosts had been present, how many bats there were previously, where they foraged and on what plant species, and whether their feeding behavior caused conflicts. Information on monthly rainfall was obtained from the meteorological station for Mandalay Region.

 

 

Results

The study species was confirmed as P. giganteus by netting two individuals on the flight path between a roost and the foraging areas (Images 1 & 2). The total number of bats counted at all three roosts during the present study was 1005 in 2003–2004 and 1513 in 2004–2005.

 

 

 

Food resources

Pteropus giganteus fed on the fruits of 24 plant species, the leaves of three species and the flowers of six species (Tables 1 and 2). The dominant families in the fruits eaten by P. giganteus were Moraceae (four species) and Myrtaceae (three species). Of the leaves and flowers consumed by the bats, the dominant family was Bombacaceae (two species). This was followed by leaves of Mimosaceae, and flowers of Bignoniaceae, Asteraceae, Caesalpiniaceae and Lauraceae.

Fruits of three species, namely Ficus rumphii, Carica papaya and Morinda angustifolia were available to bats throughout the year. Other plant species that had a long fruiting season were Ziziphus jujuba, Ricinus communis, Psidium guajava and Ficus racemosa (Table 1). Mangifera indica was found abundantly in the study area and was a dominant food source for P.giganteus in the months of April, May, June and July, which was the major local fruiting season.

 

 

 

 

Characteristics of food resources

Pteropus giganteus consumed fruits of a variety of different colours (Table 3). However, the majority of fruits observed in this study were yellow and green. All leaves were green. Six floral food resources were white, yellow and red.

Fruit species except M. angustifolia did not produce an odour strong enough for the tree to be detected by a human observer in the field (Table 3). However, most of the fruits consumed by bats had a pleasant odour when they were held close to the observer’s nose. All the flowers eaten by bats also had a pleasant fragrance.

Of all the food plants, four were small trees, three were shrubs and the remainder were larger trees (Table 3). Flowering and fruiting frequencies did not correlate with rainfall (Pearson’s correlation coefficient).

 

 

Feeding behaviour

Fruits predominated in the diets of bats throughout the year (Table 1) and leaves and floral parts of plants formed only a small proportion of the diet (Table 2). Soft fruits were either totally or partially consumed. At one foraging site (Taunginn Village), the fruit pulp of M. indica was consumed totally and the pericarp was spat out onto the ground. The bare seed was left attached to the tree by its stalk. However, it was quite common for some fruits of this species to be dropped under the tree with a little bite mark. Bats visited these mangoes in Taunginn Village and other fruiting trees near their roosts as long as they remained productive. When there were large numbers of fruits in the trees, groups of five or six bats came to them, although the number of visiting bats dwindled to one or two by the end of the fruiting season. Most bats made several flights to individual trees during the fruiting season when the village was quiet at night. Villagers believed that the bats seemed to know whether the fruits were ripe or not. If M. indica fruits were marked with tooth scratches, they become ripe the following day, and the bats ate only ripe and over-ripe fruit.

In the Ye Chan foraging site, the bats consumed all the pulp of Calophyllum inophyllum fruit and clean round seeds were observed on the ground beneath the tree during October, 2005. In April 2004, black guano containing rough fibres was encountered under the study tree (Bombax ceiba) in Taunginn Village although the fruit responsible could not be determined. In Shwe Done Village, other partially eaten fruits such as Psidium guajava and F. racemosa were observed under a F. nervosa tree. Seedlings of Nauclea orientalis and P. guajava were also found under the roost tree in Taunginn Village. Chewed leaves and flowers whose soluble contents had been extracted by the bats were collected under the day roosts. Moreover, guano with different colours reflecting the colour of the fruit pulp consumed and different coloured ejecta pellets were also found each day under the bats’ roost.

 

Attitude of villagers

The bat roosts had been present in the villages for as long as local people could remember, although numbers fluctuated from year to year. The villagers had a positive attitude towards the bats and no conflicts were apparent.

 

Discussion and Conclusion

Of the 24 species of fruits eaten by flying foxes, 13 were also eaten by local people, and of these, only three were sold in local markets—guava, mango and tamarind (Tamarindus indica). Two species (Morinda angustifolia and Azadirachta indica) were used in traditional medicine and one (Ceiba pentandra - the source of kapok) was used to stuff pillows.

In many countries the extent to which flying foxes eat fruit which is harvested and sold leads to conflict between bats and those picking and marketing the fruit. This often results in persecution of the bats (Aziz et al. in press). In the two years of this study, there has been no indication that such a conflict exists and villagers reported no conflict in previous years either. In the study area in Myanmar, a few of the fruits which the bats eat are sold commercially, and the superabundance of mangoes means that local people tolerate the fact that bats eat some of them and damage others.

In an experimental study, Andrianaivoarivelo et al. (2012) showed that Rousettus madagascariensis preferred the fruits of native plants to introduced commercial species. In the present study most plants in the diet of P. giganteus were native, and this together with the fact that there was little local marketing of species in the diet of bats may explain the absence of conflict between the bats and local people.

 

 

References

Aziz, S.A., K.J. Olival, S. Bumrungsri, G.C. Richards & P.A. Racey (in press). The conflict between fruit bats and fruit growers: species, legislation and mitigation. In: Voigt, C.C. & T. Kingston (eds.). Bats in the Anthropocene - Conservation of Bats in A Changing World. Springer, New York.

Andrianaivoarivelo, A.R., R.K.B. Jenkins, E.J. Petit, O. Ramilijaona, N. Razafindrakoto & P.A. Racey (2012). Rousettus madagascariensis (Chiroptera: Pteropodidae) shows a preference for native and commercially unimportant fruits. Endangered Species Research 19: 19–27.

Fleming, T.H. & W.J. Kress (2011). A brief history of fruit and frugivores. Acta Oecologica 37(6): 521–530; http://dx.doi.org/10.1016/j.actao.2011.01.016

Kunz, T.H. & K.A. Ingalls (1994). Folivory in bats: an adaptation derived from frugivory. Functional Ecology 8(5): 665–668.

Long, E. & P.A. Racey (2007). An exotic plantation crop as a keystone resource for an endemic megachiropteran, Pteropus rufus in Madagascar. Journal of Tropical Ecology 23(4): 397–407; http://dx.doi.org/10.1017/S0266467407004178

Thomas, D.W. (1994). Fruit intake and energy budgets of frugivorous bats. Physiological Zoology 57(4): 457–467.