Bird with super senses inspires researchers

By Birgitte Svennevig, birs@sdu.dk, 8/1/2017

All animals use a combination of several different senses to cope. But where the majority typically rely on one or two sensory systems, which are especially sensitive, the oilbird excels by apparently having keen senses all-around.

In addition to its extremely sensitive vision, the oilbird has the neural foundation for an excellent sense of smell, bristles by the beak for tactile sensation and it also uses its hearing for echolocation, which we find otherwise pretty much only in bats and toothed whales.

- This complex sensory apparatus, where the animal has the ability to combine input from so many well-developed senses, is interesting to study, says Signe Brinkløv, postdoc in the Sound, Communication and Behaviour Group at the Department of Biology, University of Southern Denmark.

Value for technological developments

As a biologist, she is interested in understanding how the oilbird uses its senses to achieve the best possible conditions in its natural surroundings.

From a more applied perspective, she is fascinated by how researchers’ knowledge of animal sensory systems can be used in the world of humans.

- We can come a long way towards understanding the individual sense. But when we begin to study how the senses complement each other and how the balance between different sensory inputs affects the behaviour of the animal when it tackles various challenges, it becomes a very complex study, which is difficult to transfer from laboratory to natural conditions. If we can learn more about it, perhaps we can transfer the knowledge to technological developments, she says.

Drones in dark forests

An example is the interaction between vision and the sense of hearing, which the animal uses when it echolocates.

With echolocation, the animal emits sounds that are returned as echoes from the surroundings and enables it to judge for example distance to the surroundings or distinguish between, e.g., food items and a rock face.

- Today, drones are often controlled manually by a drone operator who is dependent on the video footage from the drone and thus the sense of sight in order to control it. But it quickly becomes difficult to navigate with such a system in darkness or when visibility is poor. If, on the other hand, you could combine the sense of sight and echolocation on a drone so it navigates based on input from both systems, then more opportunities open up. For instance, it could fly safely and perhaps autonomously in the dark or in between trees in a forest, says Signe Brinkløv.

Does not bump into the rock face in the dark

Signe Brinkløv and her colleagues have studied the echolocation of oilbirds in Trinidad. Oilbirds are nocturnal and live in caves with up to several thousand individuals together. Every night they leave the cave to find food.

Their ability to echolocate enables them to navigate to and from their nests without bumping into the rocky walls of the cave, even in pitch black darkness.

The researchers hope that with further studies of the oilbird which investigate the interaction between vision and echolocation, a model can be developed that can be used by sensory researchers and robotics engineers.

The study was published in Royal Society Open Science.