Most songbirds migrate at night and need to recover sleep at stopover sites. In a paper published in Current Biology, we found that birds choose their sleep posture depending on their condition. Sleeping with the head tucked in the scapular feathers is associated with a lower energy consumption but also with a reduced alertness. Therefore, birds in good conditions prefer to take less risks and sleep with the head facing forward.
The project involved researchers from Austria, Germany, Sweden, and the United States. The study unveiled a new function for sleep in birds and opened new perspectives on the role of sleep in migratory strategies. If you want to learn more about how songbirds sleep during migration, follow this link.