Neuroscientists have fitted pigeons with recorders that pick up brain activity as the birds fly. The devices confirm that the birds really do use features from a landscape to find their way home. And researchers hope that they will be able to use the caps to unpick how birds use other types of navigational signals at different points in a journey.
Scientists are pretty sure from tracking experiments that pigeons use the Sun, Earth's magnetic field and possibly smells as guiding cues when navigating. In 2004, Hans-Peter Lipp, a behavioural neuroscientist from the University of Zurich in Switzerland, showed that pigeons probably also use visual information. He noted that the birds tend to turn when they hit obvious landmarks like a highway exit1.
These tracking experiments collected good information about the birds' location, by fitting modern global positioning system (GPS) loggers to the pigeons' backs. But no-one has been able to measure directly what information the pigeon are using to navigate - no one has accessed the pigeons' thoughts in flight.