A monstrous meat eating pitcher plant in Borneo has evolved a unique way to communicate with bats — in order to draw them in.
The plant, known as Nepenthes hemsleyana, communicates using special structures capable of reflecting the bats’ ultrasonic calls back to the creatures, writes Discovery News.
“With these structures, the plants are able to acoustically stand out from their environments so that bats can easily find them,” co-author Michael Schöner of Ernst-Moritz-Arndt-University of Greifswald in Germany said in a press release.
“Moreover,” he continued, “the bats are clearly able to distinguish their plant partner from other plants that are similar in shape, but lack the conspicuous reflector.”
Schöner, senior author Gerald Kerth, and their colleagues found that the bats’ droppings, which landed in and around the plants, kept them well fertilized.
The bats tend to roost near the top of the plant – away from the deadly digestive liquids contained in its inner – and the plants also benefit from this deal.
This discovery led to the study on the ultrasound communication, as the researchers wondered how the bats were drawn to the carnivorous plants as they flew by.
The scientists had a hunch that echolocation was involved in this relationship, so the scientists set up an artificial biomimetic bat head that emits and records ultrasounds. This device was used to test the acoustic reflectivity of the plant from a number of different angles, uncovering a strong reflected echo from the plant’s back walls.
After this initial finding, scientists conducted a number of behavioral experiments on the bats, which showed how the bats responded to the sounds echoed back at them. They found that the bats were better at finding obscure pitcher plants when the back walls of the plants were intact, compared to when they had been reduced.
The study also found that these pitcher plants did not have to eat as many insects as other pitcher plants because of the bat poop left around its base – adding to research that plants are able to solve problems of survival without the need for a brain.
“Carnivorous plants in general have already solved the problem of nutrient deficiency in a very unusual way by reversing the ‘normal system’ of animals feeding on plants,” Schöner said.
He continued, “It is even more astonishing that in the case of N. hemsleyana the system is taking a new turn. While N. hemsleyana reduced many insect-attracting traits, it obviously exhibits some traits that are highly attractive for a species that provides the plants with nutrients without being digested by the plant itself.”