Storks are attracted to the smell of freshly mowed grass

Researchers at the Max Planck Institute have discovered that storks are attracted to the smell of freshly mowed grass to find their preferred prey, including snails and frogs. 

While it is known that birds adapt their sight and hearing to achieve success in their environment, the new study suggests that the significance of their sense of smell has been underestimated. 

“It was simply assumed that birds can’t smell well because they don’t have real noses,” explained Martin Wikelski, director at the Max Planck Institute of Animal Behavior. “Yet they have a very large olfactory bulb in the brain with many receptor molecules for scents.” 

To investigate whether a keen sense of smell can lead birds to freshly mowed meadows, the researchers monitored the movements of white storks tagged with GPS sensors. 

“We first had to rule out the possibility that the storks could hear the tractor or see the mowing process,” said Wikelski. 

For this reason, the study only included storks that were more than 600 meters away from the mowed meadow, which means they did not have direct visual contact. 

As the mowing was underway, it turned out that only storks located downwind flew to the meadow. Those that were located upwind – and could not perceive the grass smell – did not respond. 

The researchers found that the smell of cut grass alone attracted the storks, including a field that was artificially sprayed with the scent. The results of the study contradict the assumption that storks primarily use their vision for foraging. 

“There have been storks that have flown more than 25 kilometers from the other side of Lake Constance to mowed meadows,” said Wikelski.

Based on their findings, the experts believe that sense of smell plays a previously overlooked, important role in the foraging activities of other bird species as well. They noted that birds of prey such as buzzards can regularly be seen flying over freshly mowed meadows.

The study is published in the journal Scientific Reports.

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By Chrissy Sexton, Earth.com Staff Writer