When nature calls, the toilet-shaped plants of the tropics work as the perfect bathroom for small mammals that call the forests home. In fact, by using the plants as a personal porta-potty the various mammals and insects are stimulating their own ecosystem and keeping the pitcher plants thriving.
Pitcher plants have made for a fascinating muse in the plant world as they shatter the very idea of what a plant is, eating others rather than being eaten. In fact, Charles Darwin himself was even floored by the carnivorous plant species writing in an 1860 letter to Charles Lyell, “I care more about Drosera than the origin of all the species in the world.”
Pitcher plants are truly some of the most intriguing species around. They’re known for their rather devious approach to capturing prey. Resembling pitchers (hence the name), they’re full of powerful digestive juices. When unwitting insects happen into the pool, perhaps attracted by a unique scent, they… well, they don’t tend to come back out again.
These potent plants can be very, very big, too. According to the New England Carnivorous Plant Society, the biggest pitcher plant on Earth is the Nepenthes Rajah. It can reportedly grow to three meters (almost 10 feet) tall!
That’s just the beginning of what’s so intriguing about the Nepenthes pitcher family, though. They seem to have developed a taste not only for foolhardy bugs tempted by their nectar, but also for nitrogen-rich poop.
The Poop-Pilfering Pitcher
For pitcher plants, it’s all about eating a wide range of things. More specifically, it’s about adapting to eating something else when common preferences aren’t available.
Carnivorous plants have something of a disadvantage when compared to other meat-eaters of the animal kingdom: pursuing prey is quite the issue when the most you can really move is a vigorous leaf-rustle during a heavy wind. This, then, is why pitcher plants’ nectar is so enticing to passing bugs as the plant has to lure its prey because it can’t chase or otherwise hunt them.
What happens to pitchers that live in areas without plentiful insect prey? Well, it seems they develop other ways of ensuring their nutrient needs are met.
Nitrogen is vital to the plants’ survival especially considering they are often found at higher altitudes. Accessing nitrogen it is the key reason for the pitcher plants adaptation to a poop-eating existence. The pitcher plants need the poop to come to them, as they can’t go to it. Fortunately, some animal species have ample reason to use the plants as a natural bathroom. Believe It or Not!, Kerivoula hardwickii bats and Nepenthes hemsleyana pitchers, are both found in the forest of Borneo, and have an intriguing symbiotic relationship! The plant delights in the poop of the bat, which is apparently tasty and nutritious (pitchers aren’t known for being picky, after all).
But why would the bats choose to answer the call of nature in the plants in particular, though? Well, partly because they serve as a handy (and safe) place to roost. And poop, naturally!
A Foul-Smelling Symbiotic Relationship
It’s remarkable just how much the two species rely on each other as the bats don’t only use the plants as a roost on occasion, they only roost there. Meanwhile, the pitchers, with little digestive juice in their bodies, would be ineffective at ‘eating’ the scarce few insects they may encounter. Instead, they “gain … an estimated 33.8 per cent of the total foliar nitrogen from the faeces of Hardwicke’s woolly bats.”
The arrangement seems logical enough, and it’s nice to see some mutual support among the animal kingdom (we humans all too often fall short there). What’s truly remarkable is just how rare this behavior is as it is considered only the “second case of a mutualistic association between a carnivorous plant and a mammal to date.”
It’s #ThirstyThursday and I’d like a pitcher!
🦇Hardwicke’s woolly bat visits a pitcher plant
📷Ch’ien Lee/Minden Pictures pic.twitter.com/nDkq1RsWVc
— Bat Conservation International (@BatConIntl) February 3, 2022
The most effective means of gathering poop, after all, is to serve as an enticing toilet for animals. While your average rare bat may not be a connoisseur of air fresheners, delicate potpourri arrangements or other things that may mark a human toilet as a classy establishment, they do have their preferences. These special pitcher plants, therefore, ensure their success by adapting to accommodate these preferences.
For the enormous Nepenthes Rajah, the goal of that sweet-smelling nectar isn’t to lure small invertebrates to their doom, but to attract tree shrews. Shrews, after all, are encountered more often than bugs here in the heights of this forest in Borneo, so it’s important to make the very most of what they can get. To accommodate the special guests, the plants’ entrances resemble – you guessed it – a toilet seat. What luxury for those lucky shrews! They even get a little something tasty to enjoy while they do their business. We don’t tend to get that here in the human world.
It all just goes to show that you can’t keep a good voracious giant pitcher plant down. You can poop in it, though.
By Chris Littlechild, contributor for Ripleys.com