Before revision: The radical pair model for avian magnetoreception has been significantly efficacious in explaining the magnetosensitive behavior of chemical compass . In this model, we have a multi-spin system evolving under a specific Hamiltonian assisted by neurological spin-dependent recombination channels which give an elegant compass action that many species are belived to be using .
After revision: The radical pair model has been successful in explaining behavioral characteristics of the geomagnetic compass believed to underlie the navigation capability of certain avian species .