Researchers show that migratory birds are unable to use their magnetic compass in the presence of urban electromagnetic noise. The findings open up new areas of study for magnetic sensors.
Researchers working on DARPA’s Quantum Effects in Biological Environments (QuBE) program have shown that the electromagnetic noise that permeates modern urban environments can disrupt a bird’s internal magnetic compass. The findings settle a decades-long debate into whether low-level, artificial electric and magnetic fields can affect biological processes in higher vertebrates. For DARPA, the results hint at a new class of bio-inspired sensors at the intersection of biology and quantum physics.
In an online Nature paper, research teams from the University of Oldenburg and the University of Oxford, led by Prof. Henrik Mouritsen, document a series of experiments using European robins that were carried out from 2005 to 2011.
Night-migratory songbirds like European robins have an internal magnetic compass that allows them to choose the correct migratory direction during the spring and fall migration seasons. However, when the robins used in the Oldenburg experiments were exposed to everyday levels of electromagnetic background noise, the birds failed to orient themselves correctly. When the researchers later shielded the birds from background electromagnetic noise, the birds oriented to the correct migratory direction. Birds tested in rural environments, far from sources of electromagnetic noise, required no screening to properly orient using their magnetic compass.
Electromagnetic noise is emitted everywhere that humans use electronic devices. The observations from the Oldenburg study suggest that birds utilize a biological system that is sensitive to manmade electromagnetic noise with intensities well below the guidelines for human exposure adopted by the World Health Organization.
But why is DARPA studying bird migration? According to Dr. Matt Goodman, the Program Manager for QuBE, one reason is that the observed phenomena might have their roots in quantum physics.
“Nature is an extraordinary testbed. We think it’s possible that over millions of years of evolution, biological organisms have developed systems that exploit quantum physics,” Goodman said. “The QuBE program is designed to test this hypothesis. The work we’re pursuing questions fundamental assumptions about how biological processes work.”
If manifestly quantum effects are shown to be at play in biological systems, and scientists can understand the mechanisms at work, the findings could lead to fundamentally new technologies, including bio-inspired sensors. In addition to exploring magnetic navigation, QuBE researchers are also studying photosynthesis, olfaction, and the underlying theoretical framework needed to link biology and quantum phenomena.
“The time and cost to develop many of the traditional sensors that the Department of Defense uses is substantial. Nature, on the other hand, has already evolved extraordinary capabilities — think of a dog’s sense of smell,” Goodman explained. “In addition to being extremely capable, natural sensors are also robust, durable, exhibit great sensitivity and enormous selectivity, and are produced amid the dirt and dust of the natural world; nature doesn’t need clean rooms. We’re hoping to follow nature’s lead to capture those qualities in manmade sensor systems.”