Research finds birds capable of turning natural navigation on and off

Their findings, published in the European Journal of Neuroscience, analyze white-throated sparrows and their ability to activate cluster N at night while migrating and make it go dormant while they rested during a stopover.

“This brain region is super important for activating the geomagnetic compass, especially for songbirds when they migrate at night,” said Brodbeck. “Almost all previous work on this specific brain function was done at one lab in Europe, so it was great to replicate it in a North American bird like the white-throated sparrow.”

“Magnetic fields are really fun to think about because they’re invisible to humans. We can’t see them or sense them, but most animals perceive them in some way. For birds, using Earth’s magnetic field to know if they’re going towards a pole or towards the equator is obviously really helpful for orientation and migration. It’s incredible that they can activate their brain in this way, and we can’t,” she added. 

Avoiding our "Midas" touch

MacDougall-Shackleton, AFAR co-director, a psychology professor and cognitive neuroscientist, spoke on the need to understand how animals steered themselves over long journeys and how humankind could minimize their impact on it. 

“If we want to understand bird migration or how other animals move from one place to another, we need to know how they do it. And more importantly, we need to know what we’re doing , as humans, that might influence them.”

“Birds don’t just use their magnetic compass. We know they pay attention to the Sun and the stars as cues too. And we also know that things like lights at night, or windows in buildings, and all these things that we put in the world disrupt their migrations,” he added. “This type of basic research informs us and lets us know the full suite of ways that animals perceive the world when they’re migrating and what we as humans need to do to minimize our impact.”

Study Abstract

Cluster N is a region of the visual forebrain of nocturnally migrating songbirds that supports the geomagnetic compass of nocturnal migrants. Cluster N expresses immediate-early genes (ZENK), indicating neuronal activation. This neuronal activity has only been recorded at night during the migratory season. Night-to-night variation in Cluster N activity in relation to migratory behaviour has not been previously examined. We tested whether Cluster N is activated only when birds are motivated to migrate and presumably engage their magnetic compass. We measured immediate-early gene activation in Cluster N of white-throated sparrows (Zonotrichia albicollis) in three conditions: daytime, nighttime migratory restless and nighttime resting. Birds in the nighttime migratory restlessness group had significantly greater numbers of ZENK-labelled cells in Cluster N compared to both the daytime and the nighttime resting groups. Additionally, the degree of migratory restlessness was positively correlated with the number of ZENK-labelled cells in the nighttime migratory restless group. Our study adds to the number of species observed to have neural activation in Cluster N and demonstrates for the first time that immediate early gene activation in Cluster N is correlated with the amount of active migratory behaviour displayed across sampled individuals. We conclude that Cluster N is facultatively regulated by the motivation to migrate, together with nocturnal activity, rather than obligatorily active during the migration season.