The Tropical Plant That Thrives on Shrew Poo

Sunlight and soil? That’s not all plants need to survive! In fact, some plants actually require some “meat” in their stems! Pitcher plants, for example, provide the perfect depiction of a carnivorous plant. With leaves known as pitfall traps, their prey-trapping mechanism is essentially a deep cavity filled with digestive liquid.

And while many pitcher plants digest ants and other insects to meet their nutritional needs, one type, known as Nepenthes lowii , goes for a far more unconventional diet. They actually “eat” shrew feces on a regular basis.

Believe It or Not!, the fecal matter of a shrew actually serves as a source of nitrogen for the jug-shaped, carnivorous plant. If you’re looking for that mutually symbiotic relationship, this one is truly win-win for both parties: a toilet for the mammal and a nutrient for the aerial pitcher plant. In fact, these particular pitcher plants get between 57 and 100 percent of their nitrogen from shrew feces!

A team of researchers observed the phenomenon on the island of Borneo in Southeast Asia. They discovered that mature N. lowii plants adhere themselves to vines and wind up above the ground where they can act as feces depositories. The pitcher section of their system is so large that it can hold about a half-gallon of water (and apparently quite a bit of poo, too).

Mountain shrews, in particular, enjoy licking nectar from the plant’s leaves while simultaneously defecating into its wide opening. And if this behavior wasn’t peculiar enough, scientists recorded video of the animals actually leaving their scent on the plants by rubbing their genitals on the lids. The shrews also returned to the same plants time and again. We’ve heard of dogs marking their territory, but these guys take it to a whole other level.

What’s even more interesting is that the shape of the pitcher plant is designed to make things comfortable for the shrew (after all, humans have squatty potties; shrews should have comfy toilets too!) Essentially, a shrew maneuvers its rear-end over the plant’s orifice while it licks the sugar from its lid. The feces eventually wash away into the funnel-shaped plant when it rains, keeping it clean. Sounds better than a port-a-potty!

According to scientists, insect prey is scarce in the mountainous region, so the plant adapted to survive. The nitrogen-rich feces enables it to grow, and fortunately, there are an abundance of shrews in Borneo’s high-altitude environment.

In case you were wondering,  N. lowii  isn’t the only pitcher plant that has an animal partnership. The N. hemsleyana allows wooly bats to seek shelter in its body and feeds off its droppings. “ This is considered a mutualism, because the bat provides poop to the plant, and the plant provides a roost for the bat,” according to Patty Jones , assistant professor of biology at Bowdoin College.