A new study has revealed that a pigeon’s incredible sense of direction may be down to a magnetic sensor contained in their liver.
Humans have utilized pigeons for thousands of years, depending on them to carry messages such as news or military communications. Like with animals such as fish and turtles, it’s suspected that a pigeon’s sense of direction is due in part to Earth’s magnetic field, which they use as a compass.
For almost a hundred years, scientists have been speculating on how pigeons specifically are capable of this. Some have theorized that it’s through light-sensitive molecules in their eyes, while others claim it happens in the beak or inner ear. However, a new study may have answered how.
Study assessed homing pigeons’ organs
The study, published on Science.org, surveyed the organs of homing pigeons, including the suspected eyes, beak and ear, but found a particularly strong magnetic signal in the bird’s liver.
Christian Kurts, at the University of Bonn in Germany, revealed that there are specialized immune cells in the pigeon’s liver that break down red blood cells and store iron. However, when they stripped away these immune cells and allowed the pigeons to fly without them, they “just couldn’t find their way”, suggesting that this abundance of iron in the liver might be what is giving them their sense of direction.
However, the birds’ magnetic compasses were only off on overcast days, suggesting that the sun plays a big role in their navigation. Martin Wikelski, at the Max Planck Institute in Germany, has spoken about the reliance on multiple methods of navigation.
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“Orientation and navigation are multi-sensory systems,” he said. “You use anything you can as a bird, for example, or as a mammal. Vision, smell… But in that case, if everything else fails, then you have the magnetic sense.”
The study suggests other animals, such as mice, might operate similarly, but experts have said more work is needed to find out how these liver signals reach the brain.
For more on pigeons, check out our coverage of the Reddit user who built an AI-powered pigeon defence system, or the revelation that city birds fear women more than men.
