Homing Pigeons Use Their Livers to Help Them Navigate
- 8 hours ago
- 1 min read
Scientists have long been aware that Earth’s magnetic field helps migratory birds and homing pigeons navigate, but exactly how their internal compass locks on to the magnetic field has been a mystery.
Now, scientists believe that at least part of the answer is hiding inside a seemingly random organ. Immune cells inside pigeon livers called macrophages are sensitive to the planet’s magnetic field. These cells function like an internal compass, according to a new study published in the journal Science.
Macrophages destroy old red blood cells, which makes them accumulate iron. The iron makes the macrophages superparamagnetic, a kind of magnetism that takes place in particular nanoparticles. The nanoparticles can then be magnetized if a magnetic field is applied to them.
“When pigeons fly, the nanoparticles align with the magnetic field and become ‘magnetized,’” says Clivia Lisowski, a co-author of the study. “Like that, pigeons can sense Earth’s magnetic field.”
“Our study has implications for both the immune research landscape as well as for research on animal navigation or magnetoreception, respectively. For animal navigation it’s a new concept of how animals sense/perceive Earth’s magnetic field,” Lisowski says. “We think that this ferrimagnetic mechanism can actually explain how birds migrating at night, or sharks or bats or other animals migrating in dark environments can perceive Earth´s magnetic field.”