how do birds migrate at night?

Flocks of birds prefer to migrate at night to avoid danger (Pixabe)                                                

With the end of winter and snow melting every year, birds begin their migration route to the north. However, she always prefers to migrate at night to avoid hot sun rays and predators. But have you ever asked yourself how these birds inferred their course in the dark?

External and internal factors
Migratory birds are known to rely on the Earth's magnetic field as an external compass that helps them navigate. It is believed that one of the light-sensitive proteins called cryptochrome is what helps them accomplish this task.

In a recent study by researchers from the University of Texas Southwestern Medical Center in cooperation with Southern Methodist University published in the journal "People" early this month, researchers were able to answer this question.

"We have demonstrated that cryptometrics are very effective proteins. They can sense low levels of light. So we can understand how those proteins respond in low-light situations at night as they migrate," says Brian Zultovsky, a lead researcher at the Southern Methodist University.

Search for cryptos 

These cryptosomes are found in plants and animals, and are responsible for circadian rhythms in various organisms. In birds, scientists have focused on understanding the CRY4 protein, which is a type of cryptopath. The Joseph Takahashi Laboratory - a specialist in circadian rhythms at Southwest Medical Center - focused on separating this protein and understanding its crystalline structure. On the other hand, the Zoltovsky Lab - which specializes in the study of blue light receptors - has focused on finding any unique mechanisms that this protein may use to perform its function in low-light conditions.
"Although plants and insects have light-sensitive cryptosomes that respond to the sun's rays, most vertebrates studied have non-cryptosomes," said Takahashi, head of neuroscience at the Southwest Center and associate researcher of the Howard Hughes Medical Institute. "It is effective against light. Thus, the ability and ability of the Cree 4 protein to respond to light and its influence on the Earth's magnetic field makes it one of the interesting cryptos".

The researchers separated Cree protein 4 from pigeons. Then, crystals formed from the protein, and then exposed to X-rays in a way that enables scientists to draw the atomic composition of this protein. Thus, the scientists obtained the first atomic structure of a cryptocurrency molecule that responds to light.

Although pigeons are non-migratory birds, scientists have noted the great similarity in the atomic structure of Cree4 proteins.

Migration mechanism in the dark
Researchers have discovered extraordinary changes in key areas of the protein structure that enhance the ability of these birds to collect light from the surrounding environment.

Zoltowski explains this mechanism, saying, "These cryptosomes absorb the photon of light, which in turn causes an electron to travel through a chain of amino acids. These amino acids contain three or four locations that act as a transport wire for those electrons. We have identified five locations in the toilet".

This mutation in the bathroom makes the cryptometry contain more light than it needs to be activated, so it depends less on its surrounding environment for light collection. Hence, this evolutionary feature added some efficiency to the birds. It made them less dependent on the light available in the surrounding environment, if they already had enough internal signals to migrate
Commenting on those results, Zoltowski says, "The structural structures that we obtained enable us to understand the function that these atomic structures do, and how they can use blue light to sense magnetic field lines."

"The atomic structure provides more atomic detail important to understanding how these proteins work, and thus opens the door to more detailed studies of cryptosomes in migratory organisms."