Harriers has evolved a hearing of the owl to locate the hidden prey in the tall grass

The owls, well suited to hear the exact location of the prey, have something in common with a group of unrelated raptors – Harriers.

A new study led by Canadian and Australian researchers has revealed that Harriers around the world are able to keep a much better ear for their next meal than you thought previously.

The international team of the University of Lethbridge and researchers from the University of Flinders discovered when they found unexpected owl -shaped features in the ear and the brain of several Harrier species, such as the Australian Spotd Harrier.

The new article published in the Journal of Anatomy Includes the work of the Iwaniuk laboratory of the University of Lethbridge in Alberta and “Bones and Diversity Lab” by the Associate Professor Vera Weisbecker at Flinders University in South Australia.

University of Lethbridge Ph.D. The student Sara Lemon, who directed the study, says that owls have refined hearing capacities, allowing some of their species to locate prey in total darkness.

“Until recently, it has been assumed that all their hearing adaptations were unique to the owls. However, our study shows that the Harriers have evolved independently several key adaptations to find prey by its,” she said.

The research team focused on the Harriers – a group of hawks found in North America, Australia, New Zealand, Europe and certain parts of Africa and Asia – because they show unusual and owl hunting behaviors.

Principal author and doctorate. Dr. Andrew Iwaniuk’s supervisor, associate professor at the Canadian Center for Behavioral Neuroscience, says: “Hailed people tend to drive out mainly by sight. But unlike the other Hawks, the Harriers fly low on tall grass with their beak pointed towards the ground.

“During this so-called” theft of neighborhoods “, they are not only looking for prey, but they listen to it too,” he said.

The co-author Aubrey Keirnan, a doctorate. The student at Flinders University who is also co-supervised by Dr. Iwaniuk and the associate professor Weisbecker, says that by looking at the Harrier, you can see similarities with owls.

“The Australian spotted Harrier is an excellent example,” she said. “When you look at the face of this species, you can see a distinctive disc face, which can improve their location of prey like owls.”

The discovery corresponds to older behavioral studies showing that harriers can locate sounds with a precision similar to owls, but how they do it was a mystery.

Using specimens of fauna and museum rehabilitation in Australia and Canada, the team examined the anatomy of the skull and the brain of Harriers and other species of narrowly related hawks such as the eagle with corner.

They found that, like the owls, the Harriers have enlarged the openings of the ear and two enlarged brain regions which are essential to calculate where a sound comes from.

“These hearing nuclei are in the brainstem and compare the moment when sounds arrive on the left or right ear,” explains Vera Weisbecker, an associate professor of evolutionary biology, of the College of Science and Engineering of Flinders University.

“If a sound arrives at both ears at the same time, the sound comes directly from an animal. If there is a delay, it indicates that the prey is more on the left or on the right,” she said.

“By having these two brain regions enlarge, the harriers can make such calculations more precisely than other hawks, allowing them to locate where a rat, mouse or other potential prey is hidden in the grass.”

“Harriers has therefore evolved a hearing system similar to owls, allowing them to target sounds as precisely as owls in a remarkable example of convergent evolution of the brain and behavior in animals separated by more than 60 million years”, adds the first lemon author.

The team takes care to emphasize that the hearing system of many owls is much more sophisticated than that of Harriers. This explains the capacity of certain owl species, such as the barn owl, to hunt in total darkness, while the hawks hunt only during the day.

“There are several other characteristics that help owls with their lively hearing, which we have not found in the Harriers. For example, some hiboux species have asymmetrical ears which allow them to locate sound with greater acuity, and these owls also have several other enlarged brain regions which were not enlarged at Harriers”, explains Lemon.

The team hopes that the results of their study encourage new research on the anatomy of birds to discover how a species perceives its environment.

“Anatomical studies like ours are a window on how a bird perceives the world around it, which can be extremely useful for bird conservation,” adds Dr. Iwaniuk. “For example, the dependence of harriers towards sound for prey location means that they are probably more sensitive to traffic and industrial noise. This could contribute to the major decreases of the Northern Harrier populations that we have seen in Canada.”