It’s well known that elephants have a major impact on their environment: indeed, they’re what’s known as ecosystem engineers. In a new study, Ahimsa Campos-Arceiz of the University of Tokyo reports that Asian elephant dung might serve a hitherto unreported role as a microhabitat for certain small frog species. While inspecting Asian elephant Elephas maximus dung piles on Sri Lanka in 2008, Campos-Arceiz was surprised to discover individuals of the microhylid frogs Microhyla ornata and M. rubra and a species of the dicroglossid Sphaerotheca [shown here] hiding inside or under the piles (if you need to know where microhylids fit within the anuran radiation, see the Tet Zoo article here; I haven’t gotten round to covering dicroglossids yet).
Of the 290 dung piles examined by Campos-Arceiz, six frogs were discovered (in five different piles), meaning that 1.7% of the dung piles served as homes for little frogs. Because the dung piles were also inhabited by various arthopods, there’s some indication that elephant dung piles might serve as mini-ecosystems, and loads of questions about how important dung piles might be to small frogs are now raised. Do dung piles elsewhere in the world also harbour hitherto overlooked small frogs? Notably, cattle dung piles in the same area were not found to be home to frogs, indicating that the particular conditions created by elephant dung might be ideal for frogs and the associated invertebrates [M. ornata in elephant dung shown below, from Campos-Arceiz (2009)].
Finally, Campos-Arceiz (2009) notes that this is the first recorded instance in which dung piles have been reported to serve as vertebrate microhabitats. However, that might not be true. As reviewed by Karl Shuker in The Beasts That Hide from Man, a small microbat has reportedly been observed sheltering in elephant dung piles in Kenya (Shuker 2003). One of the witnesses was Terence Adamson (brother of George Adamson of Born Free fame), who kicked a pile of elephant dung and was surprised to see a tiny greyish bat fly out of it. While the ‘elephant dung pile bat’ was never properly identified, Shuker notes ornithologist John Williams’s suggestion that it was (or is) the Horn-skinned bat Eptesicus floweri. So… bats in dung, frogs in dung, whatever next?
Thanks to Glyn Young for bringing Campos-Arceiz (2009) to my attention.
Ref – -
Campos-Arceiz, A. 2009. Shit happens (to be useful)! Use of elephant dung as habitat by amphibians. Biotropica doi:10.1111/j.1744-7429.2009.00525.x
Shuker, K. P. N. 2003. The Beasts That Hide From Man. Paraview Press, New York.