Dinosaurs may have had feathers – but it’s not for the reason you’d think
A robotosaurus.
Scientists have long thought dinosaurs may have had feathers, but didn’t know why.
Now, a very modern technique may have explained why they evolved that way millions of years ago.
Research involving a robot dinosaur revealed small omnivorous and insectivorous dinosaurs may have flapped their primitive feathered wings to scare prey out of hiding, a new study has revealed.
The robot dinosaur, called Robopteryx, was built to investigate how grasshoppers responded to different potential scaring behaviours.
It was based on the size, shape, and estimated movement range of a two-legged, peacock-sized dinosaur that lived approximately 124 million years ago called Caudipteryx.
The authors hoped the results of this experiment would help them uncover why feathered wings evolved before they were capable of flight.
They hypothesised that these proto-wings were used to startle prey out of hiding and into fleeing in order to catch them.
This tactic is known as ‘flush-pursuit’ foraging and is still observed in many contemporary birds such as the greater roadrunner and the northern mockingbird.
The researchers programmed Robopteryx to simulate this behaviour, by spreading the proto-wings and raising a tail, pausing with them outstretched, then folding them back.
The team then recorded how grasshoppers reacted to the behaviour, choosing these insects because their distant relatives existed at the same time as Caudipteryx.
‘I created computer animations imitating the hypothetical displays by Caudipteryx and presented them to grasshoppers in the laboratory,’ said Jinseok Park, a PhD student at Seoul National University, South Korea.
‘I used easily available, inexpensive equipment to record responses of neurons.’
When Robopteryx simulated the behaviour, 93% of tested grasshoppers fled compared with 47% fleeing without any proto-wings.
The results, published in Scientific Reports, also showed that grasshoppers fled more often when tail feathers were present and when the proto-wings had white patches, compared to when they were plain black.
The researchers suggest that dinosaurs’ prey would have been more likely to flee when proto wings made of feathers were present.
They were most effective near the end of the forelimbs and with contrasting patterns, and when the tail feathers, especially of a large area, were used during hypothetical flush displays – suggesting dinosaurs themselves could be more colourful than thought.
‘We propose that using plumage to flush prey could increase the frequency of chases after escaping prey, thus amplifying the importance of proto-wings and tails in manoeuvring for successful pursuit,’ said associate professor Sang-im Lee.
‘This could lead to the development of larger and stiffer feathers as these would enable more successful pursuits and more pronounced visual flush-displays.’
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