  Magnetic-sensitive radical-ion-pair reactions are understood to underlie the
biochemical magnetic compass used by avian species for navigation. Recent
experiments have provided growing evidence for the radical-ion-pair
magnetoreception mechanism, while recent theoretical advances have unravelled
the quantum nature of radical-ion-pair reactions, which were shown to manifest
a host of quantum-information-science concepts and effects, like quantum
measurement, quantum jumps and the quantum Zeno effect. We here show that the
quantum Zeno effect provides for the robustness of the avian compass mechanism,
and immunizes it's magnetic and angular sensitivity against the deleterious and
molecule-specific exchange and dipolar interactions.
