Tropical pitcher plants are among the planet’s stranger species, digesting ants and other insects that slip and fall into their bowls.

But Nepenthes lowii, a pitcher plant found in Borneo, is stranger still. It gets its nutrition not from insects but from tree shrews, which use the plant as a toilet.

Image The feces of tree shrews provides nitrogen to Borneo pitcher plants. Credit... Ch'ien C. Lee

Jonathan A. Moran of Royal Roads University in British Columbia, Charles M. Clarke of Monash University in Malaysia and colleagues describe this “novel nitrogen sequestration strategy” in a paper in Biology Letters. Using isotopic analysis, they estimate that shrew feces deposited in N. lowii’s pitchers are a significant source of nitrogen for the plants.