Visit Organic Bouquet, the world’s first online organic florist, from our website and Lubee will receive a 10% donation for each order of organic flowers purchased.
Back to Conservation Programs
Malaysia is officially home to 118 species of bats (Simmons, in press). For most people, however, this remarkable diversity is rendered invisible by the nocturnal, secretive habits of most bats. The lesser dog-faced fruit bat, Cynopterus brachyotis, is a notable exception. The roosting ecology of this harem-forming species make it a familiar sight in city parks and landscaped university campuses, where C. brachyotis males construct “tent” roosts by chewing the veins of large-leafed fan palms, causing the sides to collapse, creating a semi-enclosed roost cavity. In suburban back gardens and agricultural areas, less industrious males are frequently observed roosting at the apex of ready-made tents formed by the drooping fronds of coconut and oil palms. Depending on a male's popularity and the carrying capacity of his roost he may be joined by as many as 20 females. An earlier study of the roosting habits of C. brachyotis in disturbed habitat in peninsular Malaysia found that 16/20 roost plant species were non-endemic (Tan et al. 1997). Likewise, dietary analysis of the same population revealed that the bats relied heavily on the fruit of cultivated palms (Tan et al. 1998). Surprisingly, given its successful adaptation to anthropogenic environments, C. brachyotis is also considered to be one of the most common fruit bats in Malaysian lowland rainforest (Francis 1990; Zubaid 1993). So what does a bat that flourishes in anthropogenic environments do in its presumptive ancestral habitat, primary forest? How ecologically flexible can a single species be?
These are the questions that led to Lubee Bat Conservancy part funding Campbell 's Ph.D. research. Under the supervision of Kunz and Schneider and with the help of Malay collaborators Adnan and Zubaid, her approach to finding answers integrates evolutionary and ecological methods. Between June 2001 and January 2004 Campbell spent 18 months in peninsular Malaysia collecting ecological data and samples for genetic analysis. Field sites were established at two localities where agricultural/suburban areas border sizable tracts of primary and mature secondary forest. The roosting and foraging ecology of C. brachyotis was compared across habitat types by radiotracking bats concurrently in forested and disturbed habitats. In addition to standard morphological measurements, 2 mm 2 biopsies were collected from the wing membranes of each individual. These tiny pieces of tissue contain more than enough DNA to address questions about the recent evolutionary history of C. brachyotis . However, before she could return to the lab, Campbell began to notice some striking differences between C. brachyotis populations across the habitat types. Like those in disturbed habitat, bats in the forest roosted in foliage and under palm fronds, and social groups contained a single adult male. But harems were small--typically 1-3 females--and while both males and females exhibited low roost fidelity, changing roosts frequently within a small home range, harem groups were highly cohesive with females generally remaining faithful to a single male for the duration of the 8-10 week radiotracking periods. In contrast, males in disturbed habitat rarely switched roosts and harem group sizes fluctuated as individual females moved regularly between the roosts of several harem males. Moreover, despite the proximity of the two habitat types, radiotracked individuals always roosted in the habitat in which they were initially captured. Nighttime radiotracking confirmed the apparent ecological segregation of the two populations: ignoring the abundance of fruit trees in adjacent suburban and agricultural areas, forest-roosting C. brachyotis foraged exclusively in this habitat. Likewise, although disturbed habitat C. brachyotis routinely flew 5-10 kilometers in nightly foraging bouts, these bats did not take advantage of the forest fruits and flowers available 1-2 kilometers from their day roosts sites. It also became apparent that the phenotypes of the habitat-specific C. brachyotis populations were subtly but consistently differentiated: bats in disturbed habitat were slightly larger, had longer ears and a longer rostrum, and the orange collar of adult males was a shade duller than that of their forest counterparts.
Although analysis of ecological and morphological data is still underway, the raw data suggest strongly that Malaysian C. brachyotis are currently divided into two habitat-specific, ecologically distinct populations that, for management and conservation purposes, should be treated as separate species. But what about the evolutionary history of these bats? The anthropogenic habitat that the larger C. brachyotis thrives in today didn't exist a century ago. Has a single species undergone rapid ecological divergence as a consequence of recent human activity? Evidence from DNA says no. Analysis of mitochondrial DNA sequence data indicates that the species currently referred to as C. brachyotis has been split into two evolutionarily distinct lineages for several million years. What this means is that, despite enough morphological similarity to fool several generations of taxonomists, and despite present day co-existence as ecological neighbors, the two C. brachyotis ecomorphs have been ecologically autonomous at least since the major climate changes during the Pleistocene.
Is Malaysia in fact home to 119 species of bats? Campbell and her collaborators think so; once all analyses are complete taxonomic revision of C. brachyotis in Malaysia will be recommended. This revision will be crucial, not just for the sake of the correct naming and cataloguing of species, but because classifying forest C. brachyotis as a distinct species may significantly change the future conservation status of these bats. While forest C. brachyotis are still relatively common, the habitat that this and other forest-restricted fruit bat species depend on is highly fragmented and continually encroached upon by human activities. An important consequence of this study will be recognition that forest C. brachyotis are in fact not ecologically flexible enough to be invulnerable to the ongoing fragmentation and destruction of the habitat they depend on.
Francis, C. F. 1990. Trophic structure of bat communities in the understorey of lowland dipterocarp rain forest in Malaysia . Journal of Tropical Ecology 6:421- -431.
Simmons, N. B. In press. Order Chiroptera. In Mammal Species of the World: A Taxonomic
and Geographic Reference (D. E. Wilson and D. M. Reeder, eds.). Third edition, Smithsonian Institution Press, Washington , D.C.
Tan, K. H., A. Zubaid, and T. H. Kunz . 1997. Tent construction and social organization in Cynopterus brachyotis (Muller) (Chiroptera: Pteropodidae) in Peninsular Malaysia. Journal of Natural History 31:1605--1621.
Tan, K. H., A. Zubaid, and T. H. Kunz . 1998. Food habits of Cynopterus brachyotis (Müller)
(Chiroptera: Pteropodidae) in Peninsular Malaysia . Journal of Tropical Ecology 14:299--307.
Zubaid, A . 1993. A comparison of the bat fauna between a primary and fragmented secondary forest in
Peninsular Malaysia . Mammalia 57:201--206.
Back to Top
