The discovery of the use of magnetic navigational information

Abstract

The magnetic field of the Earth provides animals with various kinds of information. Its use as a compass was discovered in the mid-1960s in birds, when it was first met with considerable skepticism, because it initially proved difficult to obtain evidence for magnetic sensitivity by conditioning experiments. Meanwhile, a magnetic compass was found to be widespread. It has now been demonstrated in members of all vertebrate classes, in mollusks and several arthropod species, in crustaceans as well as in insects. The use of the geomagnetic field as a ‘map’ for determining position, although already considered in the nineteenth century, was demonstrated by magnetically simulating displacements only after 2000, namely when animals, tested in the magnetic field of a distant site, responded as if they were physically displaced to that site and compensated for the displacement. Another use of the magnetic field is that as a ‘sign post’ or trigger: specific magnetic conditions elicit spontaneous responses that are helpful when animals reach the regions where these magnetic characteristics occur. Altogether, the geomagnetic field is a widely used valuable source of navigational information for mobile animals.

Relaxometry with Nitrogen Vacancy (NV) Centers in Diamond

“…Naturally occurring magnetites are found in a wide range of organisms, from magnetotactic bacteria 41 and molluscs 42 to humans. 43 They are thought to be involved in the sensing of magnetic fields, 44 as well as the development of some diseases, 45 such as Alzheimer’s. Certain paramagnetic species, such as iron, copper, and manganese, as well as free radicals, are naturally ubiquitous in biological samples, whereas gadolinium is widely used for labeling.…”

A perspective on neuroethology: what the past teaches us about the future of neuroethology

“…At first glance, too weak to be detected by receptors and too sensitive for electromagnetic disturbances, the behavioral relevance of the earth's magnetic field has often been questioned. However, behavioral studies convincingly demonstrate that many organisms indeed use the earth's magnetic field for orientation (Lohmann et al 2022;Wiltschko and Wiltschko 2022). Aside from the behavioral evidence, physiological processes underlying magnetosensation are less clear (Putman 2022).…”

Uncovering loggerhead ( Caretta caretta ) navigation strategy in the open ocean through the consideration of their diving behaviour

“…Figure 3a shows the nine tracks (nos. 4,7,9,10,13,16,17,20,21) that enter the WMC influence zone (above the 5°S parallel) during its period of activity. Therefore, these tracks cross both a region of high (region A) and of low (region B) vertical current shear during equivalent periods of the year.…”

“…Decades of scientific work have shed new light on this remarkable feat, and numerous experiments have already demonstrated the ability of migrating animals such as birds, salmon, sea turtles and many other taxa, to rely on the Earth's magnetic field for navigation [5][6][7][8][9][10]. Although the clear understanding of the exact navigation mechanisms involved during the migration of these animals is still an active research topic, its potential at providing sufficient orientation cues to reach a far target has been demonstrated in many studies [11][12][13][14].…”