Written by Michael Gerhard Schöner and Caroline Regina Schöner.
Here we present our new study on the unusual interaction between bats (Kerivoula hardwickii hardwickii) and carnivorous pitcher plants (Nepenthes). Using radio-telemetry we discovered that the bats exclusively used two pitcher plant species as roosts in Brunei Darussalam. Nepenthes hemsleyana benefits from its inhabitants by gaining nutrients from their feces. In contrast, Nepenthes bicalcarata cannot gain any nutrients because all pitchers in which we found bats were either wilted or had small holes at their base through which the fluid had drained off. Our research on the microclimate inside the pitchers, the parasite infestation and the body conditions of the bats that had used either Nepenthes hemsleyana or Nepenthes bicalcarata indicates that Nepenthes hemsleyana is a higher quality roost for the bats. However, Nepenthes bicalcarata is more common throughout north-western Borneo than Nepenthes hemsleyana. By additionally using these lower quality roosts the bats are able to expand their range.
Our study shows how the local supply of roosts with different qualities affects the behavior and body condition of their inhabitants and—as a consequence—how the demand of the inhabitants can influence evolutionary adaptations of the roost providing species.
Schöner, C.R., M.G. Schöner, G. Kerth & T.U. Grafe (2013): Supply determines demand: influence of partner quality and quantity on the interactions between bats and pitcher plants. Oecologia, Online first. DOI 10.1007/s00442-013-2615-x
Please also notice that our first publication on this subject is now freely available and is attached.
Grafe, T.U., C.R. Schöner, A. Junaidi, G. Kerth &M.G. Schöner (2011): A novel resource-service mutualism between bats and pitcher plants. Biology Letters 7: 436-439.