Summary

When birds disappear at night, where do they go and what are they doing? Most of them are sleeping, of course. But sleep in birds differs greatly from what you and I do.

In this episode, we discuss the most important functions of sleep in birds. Then we get into the evolution of sleep in birds.

Along the way, we’ll talk about the similarities and differences of sleep between birds and mammals like us.

Last, we cover where and how birds sleep, regarding location, posture, etc.

Links to Some Things Mentioned in this Episode

• Avian Sleep Group at the Max Planck Institute for Ornithology
• Common Swifts Fly for 10 Months Without Landing
• The bird-like dinosaur Mei Long (“Sleeping Dragon”)

Photos of some birds mentioned

Research Citations

• Using infrared thermography to detect night-roosting birds (Mitchell and Clarke. 2019. Journal of Field Ornithology)
• Sleep and sensorimotor integration during early vocal learning in a songbird (Shank and Margoliash. 2009. Nature)
• Evidence that birds sleep in mid-flight (Rattenborg et al. 2016. Nature Communications)
• Daytime naps in night-migrating birds: behavioural adaptation to seasonal sleep deprivation in the Swainson's thrush, Catharus ustulatus (Fuchs et al. 2006. Animal Behaviour)
• Adaptive Sleep Loss in Polygynous Pectoral Sandpipers (Lesku et al. 2012. Science)
• A phylogenetic analysis of the correlates of sleep in birds (Roth et al. 2006. Journal of Sleep Research)
• Ostriches Sleep like Platypuses (Lesku et al. 2011. PLOS One)
• Sleeping Unsafely Tucked in to Conserve Energy in a Nocturnal Migratory Songbird (Ferretti et al. 2019. Current Biology)
• Night Watch in One Brain Hemisphere during Sleep Associated with the First-Night Effect in Humans (Tamaki et al. 2016. Current Biology)

Errors and Clarifications

• I said that the fossil of the bird-like dinosaur Mei Long (“Sleeping Dragon”) was discovered in 2010. It was actually discovered in 2004. 

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