They were able to sample bats from nearly all known populations, and thus could compare genetic and acoustic differences between the allopatric Myanmar and Thai populations and within the geographically continuous Thai population. Their findings suggest that it is geographic limitations on gene flow that promote sensory divergence via local adaptation. The paper is open access and can be viewed/downloaded here.

Sebastien J. Puechmaille, Meriagdeg  Ar Gouilh, Piyathip Piyapan, Medhi Yokubol, Khin Mie Mie, Paul J. Bates, Chutamas Satasook, Tin New, Si Si Hla Bu, Iain J. Mackie, Eric J. Petit and Emma C. Teeling (2011). The evolution of sensory divergence in the context of limited gene flow in the bumblebee bat. Nature Communications 2, 573. doi: 10.1038/ncomms1582.

The study is dedicated to the memory of Professor Daw Tin Nwe of Yangon University, a great supporter of bat research and international collaborations in Myanmar.

Although all six species are co-distributed across the large Krau Wildlife Reserve, they have different roosting and social ecologies, and different patterns of local dispersion. This generated predictions of genetic structure at fine to landscape scales. The spatially explicit genotype data did indeed reveal differences in the extent of movement and gene flow and genetic structure across continuous intact forest. As might be expected, highest positive genetic structure was observed in tree-roosting taxa that roost either alone or in small groups, but there was a complete absence of genetic autocorrelation in the cave-roosting colonial species. The study was motivated by the need to understand how interspecific differences in roosting ecology and social structure might influence the natural limits of gene flow in unmodified habitat as a basis for predicting the impact of landscape-scale forest clearance and fragmentation.

Stephen J. Rossiter, Akbar Zubaid, Adura Mohd-Adnan, Matthew J. Struebig, Thomas H. Kunz, Sucharita Gopal, Eric J. Petit and Tigga Kingston (2011). Social organization and genetic structure: insights from co-distrubted bat populations. Molecular Ecology DOI: doi: 10.1111/j.1365-294X.2011.05391.x

Email tigga(dot)kingston(at)ttu(dot)edu  or s(dot)j(dot)rossiter(at)qmul(dot)ac(dot)uk for a pdf copy

Working in forest fragments embedded in oil palm and rubber plantations surrounding a large tract of primary forest in Peninsular Malaysia, the authors found the expected decline in species richness with fragment size, and that, as Struebig had previously reported, this relationship was driven by bats that not only forage in forests, but roost in foliage and tree hollows within them (“forest bats”). To look at the relationship between fragment size and genetic diversity (allelic richness) they focused on three species that are relatively common in the large primary forest (Krau Wildlife Reserve), but which were expected to differ in their response to fragmentation. The cave-roosting colonial Rhinolophus lepidus is highly vagile and from Matt’s earlier work, does not show an abundance response to fragmentation.   R. trifoliatus and Kerivoula papillosa both roost within the forest in vegetation (R. trifoliatus) or small tree hollows (K. papillosa) and have small home ranges, and were expected to show a reduction in genetic diversity. This is largely what the authors found; while the genetic diversity of R. lepidus captured in forest fragments didn’t differ from those in continous forest, there was a reduction in genetic diversity in fragments relative to continous forest in both R. trifoliatus and K. papillosa, and for the latter, this decline correlated significantly with fragment area.  

The article is currently available for download from Ecology letters here

Struebig, M. J., T. Kingston, E. J. Petit, A. Zubaid, A. Mohd.-Adnan, and S. J. Rossiter (2011). Parallel declines in species and genetic diversity in tropical forest fragments. Ecology Letters 14:  580-590.