Natures wonders: living on feces (Introduction)

by David Turell , Monday, December 12, 2016, 14:58 (2685 days ago) @ David Turell

We all know about the Venus fly trap, an ingenious plant that supplements its photosynthetic diet by trapping insects. Here is a pitcher plant that uses baat dung, by inviting the bat with a place to stay:

https://www.sciencedaily.com/releases/2016/12/161212094222.htm

"They took advantage of a natural experiment involving the woolly bat Kerivoula hardwickii, and two closely-related species of pitcher plant: Nepenthes hemsleyana and Nepenthes rafflesiana. All live in the dense peat swamp and heath forests as well as lowland rainforests of northern Borneo.

"According to Schöner: "Pitcher plants grow on nutrient-poor soils, but whereas N. rafflesiana copes with this lack of nutrients by using fluid-filled pitchers to catch insect prey, N. hemsleyana has abandoned carnivory in favour of a unique and intimate relationship with the woolly bat."

"'To provide the bat with an ideal roost, the pitchers of N. hemsleyana have evolved to perfectly fit the bat's body. Unlike other pitcher plants they contain very little fluid. And most striking of all, the backwall of the pitcher forms a parabolic dish that aids the bat's echolocation. In return for its roost, the bat hunts and pre-digests the insects, depositing them as faeces in the pitcher."

"To measure the costs and benefits of this mutualism, Schöner selected plants from both species in the field. When they produced new pitchers, she blocked them with cotton wool and cling-film to prevent bats or insects from entering.

"She then fed the pitchers by hand with bat faeces, insects, or a mixture of the two, and measured their growth rate, photosynthesis and nitrogen concentrations before repeating the tests in glasshouses back in Germany.

"'As the hypothesis suggests, N. hemsleyana fed on bat faeces had the highest rates of growth and photosynthesis, and the highest nitrogen levels, showing that it benefits by efficiently outsourcing prey capture and digestion to its mammal mutualists and strongly benefits from this ecological outsourcing," explains Schöner.

"'By interacting with bats N. hemsleyana has access to a wide variety of insects because bats are better hunters than plants. And because the bats have predigested the insects, the nutrients should be easier for the plants to extract.'"

Comment: A very nice accommodation much like the cyanobacteria and barnacles. I suspect the bat found the plant, like it as a resting spot and the adaptations happened to further the relationship by epigenetics.