For a very long time, human beings have intuited that animals possess certain senses which our species does not. One of the mysteries discovered recently has to do with the magnetic sensitivity that migratory birds have, enabling them to orientate themselves during their migrations.

One team made up of physicists, chemists and biologists at the universities of Oxford (the United Kingdom) and Oldenburg (Germany) has demonstrated that nocturnal migrating birds, such as the little European robin redbreast (Erithacus rubecola) possesses a kind of internal “compass” or GPS which enables them to find their way during their thousands of kilometre-long night-time flights between northern Europe and north Africa. [1]

The robin redbreast, like many other birds, has a sort of GPS which, rather than seek signals from artificial satellites in orbit around the Earth, detects the lines of the earth’s own magnetic field. For this reason it is equally capable of migrating during the day as during the night. Researchers discovered that this magnetic sensor is in its eyes. It is an ocular protein belonging to the “cryptochrome” group, which is also present in other animals and in plants.

However, this photoreceptor protein, which is also sensitive to magnetic fields, has come to be known as “cryptochrome 4” (CRY4) and seems to be sensitive to the force lines of terrestrial magnetism that other birds such as pigeons and hens also have. In this paper the scientists explain how they tracked the genetic code that gives rise to this protein, with a view to producing it in large quantities by means of bacterial cell cultures. In the chemistry department of Oxford University, they applied magnetic and optical resonance techniques to analyse the protein, and this allowed them to discover its striking sensitivity to magnetic fields. It would appear that this sensitivity can be attributed to electron transfer reactions triggered by the absorption of the colour blue from the light spectrum.

The conclusion of the study suggests that this chemical reaction produces quantum effects capable of amplifying the magnetic signals. The electrons jump from an amino acid (tryptophan) of the cryptochrome 4 protein to the next tryptophan, thus forming radicals that are magnetically sensitive. These tryptophans seem to be the key to their magnetic compass, as if they are substituted for other different amino acids, the movement of electrons is blocked, and the robins are completely disorientated. The retina of these birds presents a complex mosaic of perfectly located and aligned cells which increase their sensitivity to the direction of the Earth’s magnetic field. This makes it possible for each robin to fly alone in the darkness of a moonless night, virtually without deviating from its migratory itinerary. They are birds that have been perfectly designed to follow, with the greatest precision, the Earth's magnetic field.

Another surprising detail is that their nocturnal flights are performed by young robins which have never done it before, and nor have they seen their progenitors do it. Science is beginning to understand the quantum mechanisms of magnetic orientation, but the question of how the young birds know exactly in which direction to orient themselves, remains a mystery, though it is assumed that it must be innate genetic programming. Can a purposeless process like random evolution programme such a sophisticated a quantum mechanism? I think not.

Other birds of a similar size, the northern wheatear (Oenanthe oenanthe), weighing only 25 grammes, covers two-way migratory distances of 30,000 kilometres between the Arctic and Sub-Saharan Africa. [2] Their migratory systems are designed with absolute precision from their first appearance on Earth, and they continue to challenge the views of many great biophysicists. Many migratory birds are capable of finding the way back to the location where they were bred, and to the very same nest where they were hatched.

How are birds with such a tiny brain, which in some cases weighs no more than a gramme, capable of performing such a feat? Now we know that it is due to the quantum mechanical effect of magnetoreception, but there may well be other navigation systems that have not yet been discovered. However, the precision of the robin’s compass or GPS, and that of other birds, is often disrupted by human activity. Electromagnetic contamination produced by AM radio waves, skews the orientation of many migratory species and deviates them from their flight paths. [3]

In my view, the words of the prophet Jeremiah are particularly relevant here:

Even the stork in the sky knows her appointed seasons, and the dove, the swift and the thrush observe the time of their migration. But my people do not know the requirements of the Lord. (Jeremiah 8 v 7).

Unfortunately, many people refuse to perceive the hand of the Creator behind so many mysteries of life, and they cling to the belief that the natural world arose spontaneously, with no divine intervention. Nevertheless, the whole of creation speaks eloquently in the opposite sense. The sorely afflicted Job also exclaims from the pages of the Old Testament: “How I long for the months gone by, for the days when God watched over me, when his lamp shone on my head and by his light I walked through darkness!” (Job 29 v 2-3) Divine light, when it illuminates the human soul, can still be our guide in the midst of the deepest darkness, just as it guides the path of so many species of birds.

Notes

[1] https://www.nature.com/articles/s41586-021-03618-9

[2] https://www.bbc.com/mundo/noticias/2012/02/120215_ciencia_pajaros_migratorios_vuelta_mundo_bd

[3] https://www.nature.com/articles/nature.2014.15176