Billions of birds migrate in and out of the US annually. Birds embark on incredible journeys globally, flying thousands of miles to reach their destination. Some birds rely on a remarkable array of senses to navigate, such as the ‘the arctic tern’, logging an astonishing distance in its lifetime- equivalent to flying to the moon and back. Birds utilize a range of senses to orient themselves, including some that are familiar to humans, and others remain a mystery to us.Birds have an impressive navigation system, they utilize various cues to navigate during migration, including sight and smell. Seasonal migrants often rely on familiar landmarks like rivers and mountain ranges, while those flying over vast bodies of water rely on their sense of smell.
How birds use the sky to find their way
Mostly birds migrate at night, as they cant rely on the sun for direction during that time, they use the stars to navigate. Specifically, the position and rotation of the stars around the celestial pole, which is marked by Polaris (the North Star). By learning the position and patterns of stars around this point, birds can determine their direction. According to LiveScience, research on the passageways of seabirds called Scopoli’s shearwaters found that blocking their nasal passages- sense of smell didn’t affect their flight over land, but they got lost over water. Birds also navigate using sun and stars, with a “sun compass” that combines the sun’s position with their integral clock. This innate GPS-like system allows them to determine their direction, and studies confirm that disrupting their internal rhythm with artificial lights throws off their navigation. Thus, highlighting the importance of this sun compass mechanism.
Multifaceted navigation system that allows birds to find their way
When the sky is cloudy and birds can’t see the sun, the stars, or other landmarks, they rely on other extraordinary senses to navigate. One such sense is magnetoreception, which allows birds to detect the Earth’s magnetic fields generated by the rippling molten metals in our planet’s core.Study shows that altering magnetic fields around pigeons disrupted their homing abilities. While the exact mechanism is not clear, Professor Peter Hore suggests that birds use some sort of chemical reaction whose outcome depends on the strength and direction of Earth’s magnetic field. Researchers have confirmed that there’s a molecule called cryptochrome, present in birds’ retinas. Cryptochrome responds to magnetic fields in lab settings, requiring blue light, but the details of its sensitivity remain unknown. Additionally, some research points to magnetoreception mechanisms in birds’ beaks, involving magnetite-interacting receptors connected to the brain. Birds also detect polarized light, using retinal cells to sense the patterns that reveal the sun’s position, even on cloudy days.
Bird navigation can aid conservation
Researchers are understanding the complex navigation systems of birds. Since birds inherit their migratory routes and distances primarily through genetics, identifying the responsible genes and their mechanisms could significantly improve conservation strategies. Also read | Astronomers discover high-altitude clouds darkening skies in YSES-1 system