A new study has revealed an unusual link between carnivorous pitcher plants and bats living in Borneo. It turns out that the plants, known as Nepenthes Hemsleyana use sonar reflecting leaves in order to communicate their location to bats so that the flying rodents can fertilize them with excrement.
Michael Schöner, co-author and member of Greifswald’s Ernst-Moritz-Arndt-University (Germany), gave a statement in a press release saying that “With these structures, the plants are able to acoustically stand out from their environments so that bats can easily find them”.
He went on to add that the bats are able to distinguish between the Nepenthes Hemsleyana and other plants that have similar looking shapes but not the conspicuous reflector.
Schöner and the rest of his colleagues started the study in an attempt to find out why so many bats of the species Kerivoula Hardwickii rooster inside the carnivorous plant’s bizarre looking structure and how exactly they manage to get they manage to find them in the first place
What the researchers found was that the plants use sonar reflectors hidden in their leaves in order to attract the bats because they need them to drop excrements in and around them, so that the Nepenthes Hemsleyana can feast on the nitrogen stored within the excrements.
In exchange for their service, the plants offer the flying mammals a safe, cool and parasite-free place to rooster. The bats move in the area towards the top, away from the carnivorous plant’s dangerous digestive liquids.
For their study, the research team used the head of an artificial biomimetic bat which emitted and recorded ultrasounds in order to assess the carnivorous plant’s acoustic reflectivity. They repeated said tests from various different positions and angles, and found that the strongest echo reflection came from the back walls of the plant. It turns out that their shape serves as a very effective reflector.
Since the bats are receptive to the sounds that are being echoed back to them from the plants, they are much better at finding the ones that have their reflectors intact. They also prefer to roost longer in these plants.
The research team was also happy to report that their findings answered another old question in the scientific community – why do Nepenthes Hemsleyana feed on so few insects compared to other similar carnivorous plants? The answer is that they don’t need to. The bat excrements provide them with all of the nutrients that they need.
Schöner felt it was important to point out that this serves as proof for how plants are able to solve complex problems, even in the absence of a brain. Carnivorous plants especially have long solved problems relating to nutrient deficiency, and not only that, but they did it by reversing what scientists refer to as the “normal system”, meaning that animals are the ones usually feeding on plants, not the other way around.
He went on to add that what’s even more remarkable is that the Nepenthes Hemsleyana has taken everything a step further – rather than attracting insects like most carnivorous plants, they’ve developed the ability to attract a species of animals that provide them with nutrients without having to be digested by the plants.
The study was published is the most recent issue of the journal Current Biology, with Brunei Darussalam University’s Ulmar Grafe serving as lead author.
Image Source: sciencemag.org