How small dinosaurs scared their prey out of hiding to eat them

By Isobel Williams via SWNS

Small dinosaurs may have flapped their little feathered wings to scare prey out of hiding, a new study has revealed.

New research using a robot dinosaur has found that small omnivorous and insectivorous dinosaurs likely flapped small, feathered primitive wings to scare prey out of hiding places.

The robot dinosaur, called Robopteryx, was built to investigate how grasshoppers responded to different potential scaring behaviors.

Robopteryx 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 that the results of this experiment would help them uncover why feathered wings evolved before they were capable of flight in some types of dinosaurs.

They hypothesized that these proto-wings were used to startle prey out of hiding and into fleeing, at which point they can be pursued and caught.

This tactic is known as ‘flush-pursuit’ foraging and is observed in many contemporary birds such as the greater roadrunner and the northern mockingbird.

To test this theory they programmed Robopteryx to simulate this behavior, 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 behavior, choosing these insects as they belong to the order Orthoptera which existed concurrently with Caudipteryx.

Jinseok Park, a PhD student at Seoul National University, South Korea, said: “I created computer animations imitating the hypothetical displays by Caudipteryx and presented them to grasshoppers in the laboratory.

"I used easily available inexpensive equipment to record responses of neurons.”

When Robopteryx simulated the behavior, 93 percent of tested grasshoppers fled compared with 47 percent fleeing without any proto-wings.

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 therefore conclude 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.

Associate professor Sang-im Lee said: “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 maneuvering for successful pursuit.

“This could lead to the development of larger and stiffer feathers as these would enable more successful pursuits and more pronounced visual flush-displays.”