Do Pigeons Navigate with Their Liver?

Animals use a variety of navigational strategies, such as memorizing important locations and tracking the stars. The Earth’s magnetic field serves as a compass for fish, birds, and turtles. A surprising gut feeling may help pigeons find their way home. However, it’s still unclear how precisely they accomplish this.

One well-known species of frequent fliers that can go hundreds of miles in a single day is the pigeon. For thousands of years, people have used them to transport news, notes, and military signals. For a long time, scientists have attempted to figure out how pigeons navigate without getting lost. Some believe birds receive magnetic cues via light-sensitive molecules in their eyes, while others believe it occurs in the beak or inner ear.

In a recent study, scientists looked for magnetic hints in the birds’ organs and discovered a significant signal in an unexpected place: the liver. The pigeon’s liver contains specialized immune cells that break down red blood cells and store iron. When scientists temporarily depleted pigeons of immune cells and allowed them to fly, the birds “just couldn’t find their way,” implying that iron-rich liver cells may play a part in their sense of direction.

The birds’ magnetic compasses were only disrupted on cloudy days. That is because they also use the sun as a navigational aid.

Scientists have previously speculated if immune cells could be involved in magnetic sensing. Immune cells are seen near nerve fibers in the liver. That could be how pigeons send their “magnetic sense” to the brain, which helps them navigate.

The scientists believe that other birds and animals, such as mice, could use a similar magnetic GPS. However, further research is needed to confirm that pigeons navigate this manner and to determine how these signals reach the brain. While the researchers discovered the highest magnetic signal in the pigeons’ livers, similar immune cells have also been located in it’s beak and spleen.

Content for this question contributed by Terri Du Charme, resident of Marinette, Marinette County, Wisconsin, USA