Some things naturally go together: peanut butter and jelly, salt and pepper, or chocolate and bacon (or is that just me?). In nature, there are other combinations that are very bizarre and unlikely. Different combinations of living things will join forces to help each other survive. We call this ‘mutualism,’ it is a type of symbiotic relationship. A common example of mutualism we experience every day is between the bacteria in our gut and ourselves. We provide the bacteria with nutrients while the bacteria aids in the digestion process. That example is simple and makes sense… but when we talk about a mutually beneficial relationship between a bat and a carnivorous plant… then things get a little interesting!
The image above portrays a symbiotic relationship between insects and plants. This is not, however, an example of mutualism because the plant host does not benefit from this relationship. The insects will chew their way into the stem of certain plants which provides them warmth and possible nutrition during the colder parts of the year. Just like these insects housing themselves inside of plant stems, so too does the Hardwicke’s Woolly Bat house itself inside of the carnivorous plant known as Nepenthes hemsleyana.
The woolly bat hunts insects during the cooler parts of the day and into the night. But during the heat of the day in the Bornean jungle the bat needs a cool place to safely roost. This is where the carnivorous pitcher plant comes into play. The plant likes the bat’s company so much, they have evolved specialized parts to accommodate their host. A longer and wider body enables the bat to fit snugly inside the plant and the plant produces lower levels of digestive fluids so as not to harm the bat while it is roosting. In return, the woolly bat poops inside of the plant. This may not sound like a mutually beneficial relationship to some (how did the plant draw the short straw?!) but the bat feces provides the plant with a higher concentration of nitrogen (a very necessary element for plants and all living things) than does its normal diet of small insects that get stuck inside the carnivorous plant. But wait, it gets more bizarre! Bats use echolocation to find moving insects to eat, but how do they find the immobile plants to roost in? The carnivorous plant, Nepenthes hemsleyana, has evolved an ultrasonic reflector which causes the bat’s sounds to bounce back to the bat in a certain way signalling that the friendly plant is nearby. This is a very impressive feat, think about it: a (virtually) blind bat in the thick, cluttered jungle of Borneo able to locate a small carnivorous plant to roost in. It’s amazing! What other strange and unlikely companionships can you find in nature? There are plenty of them out there waiting to be discovered!
THANK YOU for reading! Please comment below and let me know how I am doing to help you see your world through the intriguing lens of science.
*NOTE: The cover image on this post is not an image of Hardwicke’s woolly bat. Neither is the jungle image the Bornean jungle. The only photo in this post that is owned by the author is the second photo with the insects and the stem.