Bat cave and Hobbit hole, microbats of Liang Bua (Flores, Indonesia)

Abstract

Liang Bua is a limestone cave on the island of Flores, Indonesia. Palaeontological and archaeological excavations at this site have unearthed one of the best insular records of fossil bats to date. The assemblage is numerically dominated by the horseshoe bat species Rhinolophus euryotis, followed by the leafnosed bat Hipposideros diadema. In addition to these species, remains of Rhinolophus simplex, Hipposideros sp. cf. H. sumbae, Murina sp. aff. M. florium, Taphozous sp., Kerivoula sp. and Miniopterus sp. have also been recovered. Two taxa found in Liang Bua, Rhinolophus euryotis and Miniopterus sp., are not apparent in the modern bat fauna of Flores. Some specimens, found during the more recent excavations, are known from specific depths. Two age-groups are represented. The stratigraphically oldest is 74–61 ka and includes Murina sp. aff. M. florium and Rhinolophus euryotis. Conversely, the younger, Holocene, assemblage is much more diverse. Despite the relatively small amount of microbat material collected thus far, it displays a higher diversity than the rodents from the site. This is presumably related to the better dispersal ability of bats relative to other, non-volant mammals.

梁布亚是印尼Flores岛上的一个石灰岩溶洞。古生物学和考古学发掘已经在这个地点出土了迄今最佳的化石蝙蝠记录之一。该组合在数字上以马蹄蝙蝠种Rhinolophus euryotis 为主，其次是叶鼻蝙蝠Hipposideros diadema。除了这些物种外，还发现有Rhinolophus simplex、 Hipposideros sp. cf. H. sumbae、 Murina sp. aff. M. florium、 Taphozous sp., Kerivoula sp. 和 Miniopterus sp. 化石。在梁布亚发现的两个分类群，Rhinolophus euryotis 和 Miniopterus sp.，在Flores现代蝙蝠群中并不显著。在最近的发掘中发现的一些标本采自特定的深度。两个年龄组被代表。在最古老的地层为74-61万年，含有Murina sp. aff. M. florium 和 Rhinolophus euryotis。 相反地，较年轻的全新世组合更加多元化。尽管相对少量的小蝙蝠化石被采集，它比同一地点采集到的啮齿动物有更高的多样性。据推测这可能是因为蝙蝠比其它不会飞的哺乳动物有更好的扩散能力。

Key words:

• Liang Bua
• Chiroptera
• Flores
• taxonomy
• late Pleistocene
• Holocene.

Acknowledgements

We are most grateful to the The National Research and Development Centre of Archaeology in Jakarta and Gert van der Bergh (University of Wollongong, Australia) for making the loan of the Liang Bua Sector IV micromammals possible. The reviews by Suzanne Hand and an anonymous reviewer led to a major improvement of the manuscript after the first submission, and we are most grateful for all their comments and corrections. We dedicate this paper to Mike Morwood (1950–2013), whose name will always be connected to Liang Bua and its former inhabitants.