Numerical tests of magnetoreception models assisted with behavioral experiments on American cockroaches

TL;DR

This study investigates magnetoreception in American cockroaches through behavioral experiments with rotating magnetic fields, challenging existing models and providing insights into the biological sensing mechanisms.

Contribution

It provides experimental evidence that excludes the magnetite model and questions the radical pair model's applicability to cockroach magnetoreception.

Findings

Cockroaches show increased activity in Earth's magnetic field

Stronger magnetic fields diminish the activity response

Magnetite model is inconsistent with observed behavior

Abstract

Many animals display sensitivity to external magnetic field, but only in the simplest organisms the sensing mechanism is understood. Here we report on behavioural experiments where American cockroaches (Periplaneta americana) were subjected to rotating external magnetic fields with a period of 10 minutes. The insects show increased activity when placed in a rotating Earth-strength field, whereas this effect is diminished in ten times stronger rotating field. We analyse established models of magnetoreception, the magnetite model and the radical pair model, in light of this adaptation result. Our findings show that the magnetite model is excluded and the radical pair model requires strong additional assumptions to be compatible with the data.