Mr Tony Wood
Cheiromeles torquatus
Contact details
School of Biological Sciences, University of Bristol, Woodland Road, Bristol, BS8 1UG.
phone: +44 (0)117 954 6386 (Internal 46386)
fax: +44 (0)117 331 7985
e-mail: Tony.Wood@bristol.ac.uk
Introduction
I began studying for my PhD at the University of Bristol in 2003. Previous to this I took my BSc in Zoology at the University of Reading , obtaining a First with Honors. My final year BSc project studied resource partitioning in a guild of open space bats in Sualwesi , Indonesia . For my PhD I am studying bat diversity and activity in peninsular Malaysia and have three main objectives:
- To determine the impact of tropical forest conversion to oil palm plantation on the diversity, activity and diet of two bat assemblages, the open space and the edge/gap insectivorous bats.
- To understand the role these species play as biological agents of pest control.
- To create a comprehensive and readily available echolocation reference library for the region.
Study area
Malaysia has a significant proportion of all lowland evergreen forest in South East Asia , a habitat largely unprotected and with the highest priority for conservation protection. Biological diversity in Malaysia 's lowland forests is extremely high and is particularly apparent in bats (order Chiroptera), with 3 km² of lowland evergreen forest in Krau Wildlife Reserve, peninsular Malaysia , supporting in excess of 50 insectivorous bat species (Kingston et al ., 2003). This greatly surpasses anything previously recorded from a palaeotropic site of similar size.
Yet it is these more accessible lowland forest habitats that are most at risk of conversion to single species agriculture, such as oil palm plantations.
Oil palm ( Elaeis guineensis ), a native of West Africa, was introduced to Malaysia in the 1970's. Today, oil palm plantations account for 11.85% of the country's total land area, covering over 3.8 million hectares (Mha) (CSPI 2005; FoE 2005; MPOA 2005). Malaysian and Indonesian palm oil accounts for 83% of total production and 89% of global exports, and is forecast to become the most produced and internationally traded edible oil by 2012 (CSPI 2005). To respond to this demand new plantations are created, and in Malaysia during the period 1999-2004 an additional 1.85Mha of new oil palm was planted, with over 43% from converted forest (CSPI 2005; MPOA 2005). Malaysia and Indonesia have allocated a further 777,000ha and 6.8Mha respectively to new oil palm, bringing the total oil palm in Malaysia to 4.6Mha (CSPI 2005).
Bat ecology
Insectivorous bats are often grouped into guilds (species that exploit a similar resource in a similar way), with classification based on flight ability and echolocation call structure (McKenzie and Rolfe 1986; Aldridge and Rautenbach 1987; Crome and Richards 1988; Kalko 1995; McKenzie et al., 1995; Kingston et al., 2003). Guilds include those species exploiting forest interior, edge/gap and open space habitats. Open space habitats include rivers, streams and naturally created tree-fall gaps within the forest. Bat species of the open space guild are adapted for fast, energetically-efficient flight and have relatively high intensity echolocation calls adapted to maximize detection of widely dispersed prey items over large open areas. This contrasts with the ecomorphology of forest interior species, that show slower, more maneuverable, less energy-efficient flight (resulting in smaller home-range size) and echolocation calls that enable them to distinguish echoes from prey embedded in echoes from surrounding vegetation. Whereas forest interior species are largely confined by these adaptations to stands of undisturbed forest, open-space bats may be able to exploit the more anthropogenic habitat matrix.
Given the predicted rate of growth of Malaysia 's oil palm industry, research is urgently required on the effects of habitat fragmentation and forest conversion. The open space guild is predicted to be the most predisposed to exploit agricultural and disturbed habitats, making research on their presence, diversity and activity of high conservation value.
This study hypothesizes a loss of bat diversity in oil palm plantations compared to the forest habitat, and that the species that are lost can be predicted from ecomorphological characters.
Results
Fieldwork in Krau Wildlife Reserve, peninsular Malaysia , over 21 months (June 2003 September 2006) has resulted in over 1000 individual bat captures, comprising 28 open space and edge/gap species. Five of these species appear on the IUCN Red List for bats in Malaysia , including one species: Hesperotenus doriae , an endemic species categorized as endangered, and is the first record of this species within the reserve.
To determine bat activity and diversity in the different habitats, I am undertaking acoustic surveys. Anabat detectors (zero-crossing) and Pettersson detectors (time-expanded) can both record echolocation calls of bats in flight. These two methods complement each other, providing both continuous recordings for activity and species classification, and high level recordings for describing new species, respectively.
Analysis of echolocation calls on BatSound Pro software has enabled species identification of the three Miniopterinae present in the region: Miniopterus magnater, M. schreibersii and M. medius (see Corbet and Hill 1992). The overlap in morphology between these three species can cause problematic identification, however echolocation peak frequency provides distinct separation. The echolocation calls of many of these Malaysian species have yet to be described, or have been described in geographically distinct locations.
I am also collecting faecal pellets from captured bats and collecting a reference library of insects in the various habitats (forest/river/oil palm), to enable dietary analysis.
References
Aldridge H.D.J.N. and Rautenbach I.L. (1987). Morphology, echolocation and resource partitioning in insectivorous bats. Journal of Animal Ecology . 56 763-778.
Crome F.H.J. and Richards G.C. (1988). Bats and gaps: Microchiropteran community structure in a Queensland rain forest. Ecology . 69 (6) 1960-1969.
Center for Science in the Public Interest (CSPI). Brown E and Jacobson M.F. (2005). Cruel Oil: how oil palm harms health, rainforest and wildlife. www.cspinet.org
Corbet G.B., Hill J.E. (1992). The mammals of the Indomalayan region: a systematic review. Oxford : Oxford University Press.
Friends of the Earth (FoE). Wakker E. (2005) Greasy Palms: the social and ecological impacts of large-scale oil palm plantation development in Southeast Asia . www.foe.co.uk
IUCN Protected Areas and World Heritage (2005). www.iucn.org
IUCN Red List (2004). www.iucnredlist.org
Kalko E.K.V. (1995). Echolocation signal design, foraging habitats and guild structure in six Neotropical sheath-tailed bats (Emballonuridae). Symposium of the Zoological Society , London 67 259-273.
Kingston T., Francis C.M., Akbar Z. and Kunz T.H. (2003). Species richness in an insectivorous bat assemblage from Malaysia . Journal of Tropical Ecology . 19 1-12.
Kingston T., Jones G., Akbar Z. and Kunz T.H. (1999). Echolocation signal design in Kerivoulinae and Murininae (Chiroptera: Vespertilionidae) from Malaysia . Journal of Zoology , Lond. 249 359-374.
Malaysian Palm Oil Association (MPOA). www.mpoa.org.my
McKenzie N.L., Gunnell A.C., Yani M. and Williams M.R. (1995). Correspondence between flight morphology and foraging ecology in some Palaeotropical bats. Australian Journal of Zoology . 43 241-257.
McKenzie N.L. and Rolfe J.K. (1986). Structure of bat guilds in the Kimberley mangroves, Australia . Journal of Animal Ecology . 55 401-420.
Ministry of Primary Industries Malaysia (KPU). www.kpu.goc.my