Interactions between carnivorous pitcher plants and bats in Borneo

• Applicant: Professor Dr. Gerald Kerth
• Subject Area: Evolution, Anthropology
• Term: from 2011 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 193718648

We study an extraordinary mutualistic interaction (resource-service) between bats and carnivorous pitcher plants in Borneo. Recently, we showed that the pitcher plant Nepenthes rafflesiana var. elongata gains about a third of its nitrogen demand from faeces of Hardwicke’s woolly bats (Kerivoula hardwickii hardwickii) that exclusively roost in its aerial pitchers. We hypothesise that the extraordinary pitcher form of N. r. elongata, which makes them poor insect traps compared to other pitcher plants, is an evolutionary adaptation to serve as a day roost for bats. To investigate a possible dependence between the partners of this fascinating interaction as well as costs and benefits that they gain from their interactions, we will use a combination of: 1) field and lab observations of the bats’ behaviour towards pitcher plants, 2) field and lab experiments measuring the benefits and costs the pitcher plants obtain from the presence of the bats, 3) genetic analyses of population structures of bats and pitcher plants, and 4) chemical analyses of the nitrogen contents of pitcher plants growing under natural conditions in the field and controlled conditions in the lab. Allowing for experimental manipulation, the pitcher-plant-bat system offers an excellent opportunity to examine an exceptional form of inter-specific relationship between plants and mammals.

• DFG Programme: Research Grants
• International Connection: Brunei
• Participating Person: Professor Dr. Ulmar Grafe