Birds’ Ability to Judge Body Width Surprises Scientists

A new study suggests that birds are more likely to beat humans in tests that require quick judgment of body width. The researchers have found that birds are capable of flying in cluttered environment due to their acute sense of body position.

Birds can fly through gaps that are as narrow as their outstretched wingspan, an ability that helps them navigate through several obstacles.

The study was conducted by University of Queensland (UQ) researchers. The team wanted to study birds' flying abilities to design advanced aircraft navigation systems.

"We were quite surprised by the birds' accuracy - they can judge their wingspan within 106 per cent of their width when it comes to flying through gaps," said Dr Ingo Schiffner from UQ Queensland Brain Institute, according to a news release.

"When you think about the cluttered environments they fly through, such as forests, they need to develop this level of accuracy. When they encounter a narrow gap, they either lift their wings up vertically or tuck them in completely, minimising their width to that of their torso," he added.

In the study, birds were made to fly in environments that had several narrow gaps. The researchers used high-speed cameras to capture every movement of the birds.

Budgies were used to study birds' flying abilities. According to the researchers, these birds use optic flow to test air speed. Budgies don't have 3D vision like humans and so lack binocular overlap.

The researchers said the study will help in the development of new algorithms for future aircrafts. The algorithm could also be used to make urban drones safe. Drones require superior abilities to judge gaps and avoid collisions.

"Seeing in three dimensions requires two eyes or cameras with sufficient visual overlap, so using optic flow with just one camera would be very useful, saving weight and keeping autonomous vehicles small."

Birds aren't the only creatures that are helping researchers design more efficient air craft. University of Queensland researchers have already used cues from bees to develop an advanced aircraft landing system.

The study is published in the journal Frontiers in Zoology.