Pigeons fitted with neurologgers and mini global positioning systems reveal navigation secrets!
Homing pigeons have been used for centuries to carry messages and have been known to cover hundreds of kilometers in a single journey. Previous studies had suggested that they used indicators such as the position of the sun in the sky, the Earth’s magnetic field and even their sense of smell to find their way around. Now a team lead by a Zurich-based scientist has created a tiny device that reads the birds’ brain waves while they fly, showing that pigeons appear to recognize places of interest as they navigate. To peer into the world of the pigeons, Vyssotski, a research fellow at Zurich University’s Institute of Neuroinformatics, developed a device called the neurologger. The apparatus weighs just two grams and contains an electroencephalograph (EEG), a system that records electrical activity in the brain. The team then outfitted 26 test birds with neurologgers and mini global positioning systems before setting them free on the Italian coast of the Mediterranean Sea at distances of up to 30 kilometers from their home lofts.
The data revealed a surprise. Vyssotski said that low frequency brain waves, which his team had been concentrating on in earlier studies, were not as important as thought. It was found that middle and high frequency brain waves correlate with the animal behavior better. Scientists found that these middle and high frequency brain waves were relatively inactive when the pigeons flew over the sea but were much busier when they approached the coastline. When the team released the birds in a suburb, the same frequencies spiked as the birds passed over features such as roads. Through a series of experiments conducted on the type of homing pigeons once used by the Swiss army, scientists were able to see what happens in the birds’ brains as they fly.