Avian Magnetoreception Navigation Systems: A Biophysical Marvel

Abstract

Migratory species of birds can navigate using the earth’s weak magnetic field. This is believed to

be made possible by two biophysical magnetoreception systems. One of which, uses the radical

pair mechanism and occurs in the short-wavelength cones of the retina; utilizing light-induced

oxidation of a cryptochrome, followed by a further light independent oxidation of the resulting

species in the presence of a weak magnetic field. The latter part of this process being the crucial

step in the radical pair mechanism since it is sensitive to the physical orientation, relative to the

magnetic field vector lines, because of its electron-spin characteristics. The second occurs via a

small deposit of iron-rich structures found in the beak by which information is electro-

physiologically transmitted through the ophthalmic nerve. The navigational framework by which

birds interpret these senses is still poorly understood; however, current literature suggests the use

of both magnetoreception systems, polarity independence, magnetic field intensity sensitivity,

and a navigation framework that utilizes inclination with respect to the local magnetic field.

Find the full condensed literature review paper here.