Birds have good memories, but in contrast to mammals, little is known about how they consolidate memories during sleep. Researchers from the Max Planck Institute for Ornithology and Utrecht University recorded waves of slow activity traveling through the brain of sleeping pigeons that are very similar to those observed in mammals. However, they could not detect other brain rhythms known to be important for certain types of memory consolidation in mammals. They therefore suggest that birds may process some memories in a different manner from mammals.