Researchers are utilizing robotic dinosaurs in an attempt to elucidate the evolution of birds’ feathers.
Being knowledgeable about the behavior of dinosaurs presents a challenge as there is limited information that can be extracted from the fossilized remains of creatures that passed away millions of years ago.
Researchers in South Korea faced a unique challenge when there were no living creatures to observe. They came up with a solution: Robopteryx. This robot closely resembles a prehistoric omnivorous bird called Caudipteryx, if one ignores its wheels.
The researchers created a device to examine their theories on the beginnings of birds’ wings and tails. Prior to the initial flight with feathers, certain dinosaurs evolved forearms and tails with feathers, but these were not strong enough to allow for flight. The exact cause of this evolutionary change is still a topic of discussion.
Paleontologists have suggested various advantages for the existence of small “proto-wings”. These potential benefits include acting as insect catchers, aiding in prey capture, facilitating longer jumps and gliding, and providing warmth for the dinosaur and its young.
Another possible theory suggests that dinosaurs may have utilized their feathered limbs to intimidate and scare away insects and other potential prey from their hiding spots. This strategy, known as “flush and pursue,” is still used effectively by modern animals like the northern mockingbird and greater roadrunner.
The researchers conducted an experiment by placing Robopteryx in front of unsuspecting grasshoppers and having it perform various wing and tail movements. These movements were intended to imitate possible displays performed by Caudipteryx approximately 124 million years ago during the early Cretaceous period.
According to Prof Piotr Jablonski, a member of the behavioural ecology team at Seoul National University, we approached the grasshopper cautiously and slowly so as not to startle it and cause it to run away.
The scientists published a report in Scientific Reports detailing the results of their study on grasshopper behavior when approached by Robopteryx. They found that the grasshoppers were more likely to flee when the robot deployed its wings, particularly when it performed a sweeping and swooping motion. The researchers also noted that adding white patches to the black wings and large tail feathers to the display increased the frequency of escape responses from the insects.
As Robopteryx neared, several grasshoppers leapt away, while others remained still or sought cover behind a plant stem, ready to flee. According to Jablonski, in this scenario they blend in and are not as noticeable as when they make a sudden jump.
The scientists believe that flat screens activate ancient escape pathways in the insect’s brain. This defense mechanism causes the grasshopper to run, but also puts it at a higher risk of being eaten by a predator. If feathered dinosaurs also used this tactic while hunting, it could have led to the development of bigger and stronger feathers, according to their theory.
But other scientists may require more persuasion. Jablonski mentioned that the team encountered “several rejections” from 11 journals before the study underwent review and was ultimately accepted for publication in Scientific Reports.
Michael Benton, a professor of vertebrate palaeontology at the University of Bristol, expressed hesitation about the idea. He acknowledged that flight-type feathers first appeared in dinosaurs with small wings that were too small for powered flight. However, he pointed out that these pennaceous feathers were specifically adapted to create a continuous wing surface and may have been used by early feathered dinosaurs for gliding between locations.
Many individuals claim that having half a wing is pointless, but in reality, this is a common feature among modern gliding reptiles and mammals, making it a useful adaptation for flight or gliding without the use of power.