How pigeons exploit magnetic fields for navigation
Source: Ars Technica
[Image: Electron microscopy image of pigeon liver tissue shows hepatic macrophage (blue) in contact with a nerve fiber (yellow), enabling transmission of “magnetic” information to the pigeon brain.]
Study Overview
All pigeons in the control group successfully navigated back to the aviary. In contrast, pigeons that received clodronate injections lost their sense of direction and did not return home until the following day, when the sun was out. A follow‑up experiment with the clodronate‑treated pigeons under sunny conditions showed no impairment of homing ability, indicating that they could rely on solar cues.
These results suggest that pigeons combine the sun’s orientation with magnetic sensing to navigate, revealing a previously unsuspected mechanism for magnetoreception in animals.
Implications for Other Species
The authors propose that similar mechanisms could explain magnetoreception in:
- Bats and blind mole rats, which lack functional cryptochromes or live in low‑light environments.
- Certain shark species, such as scalloped hammerhead sharks, which appear to orient using geomagnetic anomalies associated with seamounts.
“Beyond magnetoreception, our findings contribute to a broader emerging concept: tissue‑resident macrophages can function as peripheral sensory cells, providing direct, biologically meaningful feedback to the brain,” the authors concluded.
Perspective and Caveats
In an accompanying perspective, Simon Spiro (Zoological Society of London) and Hal Drakesmith (University of Oxford) highlighted several concerns:
- The iron‑rich cells observed in the liver might result from the diet of captive pigeons, as many zoo‑housed animals exhibit iron overload.
- It remains unclear whether the liver is the most plausible organ for magnetic sensing.
- Clodronate treatment could have depleted macrophages in other body regions, potentially confounding the histological findings.
Spiro and Drakesmith also referenced a 2025 study that employed a more global methodology, suggesting an alternative mechanism: specialized cells in the pigeon forebrain encode magnetic information, facilitating navigation. Both mechanisms operate without light stimulation, raising the possibility of multiple, complementary processes.
“Perhaps one process dominates for long‑distance navigation, whereas another is used for more specific destination‑finding, with both operating with different degrees of precision,” they concluded. “Indeed, it could be prudent to have more than one way of getting home in the dark.”
References
- Lisowski et al. (2026). Science. DOI: 10.1126/science.ady2486
- Spiro, S., & Drakesmith, H. (2025). Science. https://www.science.org/doi/10.1126/science.aea6425
- About DOIs: Ars Technica article