A decisive, untried test of the hybrid magnetite/radical-pair avian magnetic compass: protocol for Emlen-funnel trials under 0.05-10 mT static fields
Two mechanisms claim to explain the avian magnetic compass. The radical-pair model (cryptochrome-4 in the retina) predicts that compass information saturates as an applied static field grows from 0.05 to 10 mT. The newer hybrid model (Hore et al., PNAS 2026) adds a single-domain magnetite nanoparticle that amplifies th...