Research into how animals move around the world helps determine the influence of human activity
The Earth’s magnetic field, generated by the flux of molten iron in the inner core of the planet, extends into space and protects us from cosmic radiation emitted by the Sun. It is also, remarkably, used by animals like salmon, sea turtles and migratory birds for navigation.
But how? And why? A new study by researchers at Western’s Advanced Facility for Avian Research (AFAR), home to the world’s first hypobaric climatic wind tunnel for bird flight, explores a region of the brain called cluster N that migratory birds use to perceive the earth’s magnetic field. The team discovered that the region is activated in a very flexible way, which means that these birds have the ability to process or ignore geomagnetic information, just like you can play music when interested or turn it off. when you are not.
Specifically, the research team led by psychology PhD candidate Madeleine Brodbeck and AFAR co-director Scott MacDougall-Shackleton studied white-throated sparrows and found that they were able to activate group N at night when motivated to migrate (to avoid prey and fly). during cooler periods) and put it dormant when resting at a stopover site
This is the first demonstration of the functioning of this brain region in a North American bird species, as all previous research in this area has been carried out in Europe.
“This region of the brain is extremely important for activating the geomagnetic compass, especially for songbirds when migrating at night,” Brodbeck said. “Almost all previous work on this specific brain function has been done in a lab in Europe, so it was great to replicate it in a North American bird like the white-throated sparrow.”
The Earth’s magnetic field, probably first studied and identified by German mathematician Carl Friedrich Gauss in the 1830s, has long fascinated physicists, aerospace engineers, and even science fiction writers like Frank Herbert and Stephen King. Brodbeck, a bird psychologist, is also intrigued.
“Magnetic fields are really fun to think about because they’re invisible to humans. We can’t see or feel them, but most animals sense them in some way,” Brodbeck said. “For birds, using the earth’s magnetic field to know if they are heading towards a pole or towards the equator is obviously very useful for orientation and migration. It’s amazing that they can activate their brains in this way. way, and we can’t.”
Understanding the physical mechanisms of how animals move around the world is a fundamental question for researchers, says MacDougall-Shackleton, professor of psychology and cognitive neuroscientist.
“If we want to understand bird migration or how other animals move from place to place, we need to know how they do it. And more importantly, we need to know what we do, as humans, who might influence them,” MacDougall-Shackleton said.
The results were published in the journal European Journal of Neuroscience.
“Birds don’t just use their magnetic compass. We know they also pay attention to the Sun and the stars as clues. And we also know that things like lights at night, or building windows, and all those things that we put in place the world disrupts their migrations,” MacDougall-Shackleton said. “This kind of basic research informs us and allows us to know the full range of ways that animals perceive the world when they migrate and what what we as humans need to do to minimize our impact.”