Last time we learned about how birds preform their great feats of migration. This week we learn about the long scientific history and the many experiments ornithologists conducted to discover the truth of how they do. From birds on the moon and sleeping under frozen ponds to satellite tracking, we've come a long way with our science. Join me as we retrace the theories.

Also see if you can spot the places that were re-recorded...

NOTES

• Birds on the Moon: https://www.wired.com/2014/10/fantastically-wrong-scientist-thought-birds-migrate-moon/
• Ain't no air in space: https://www.bbc.com/future/article/20160419-the-victorians-who-flew-as-high-as-jets
• Hibernating Swallows: https://press-files.anu.edu.au/downloads/press/n5194/html/11_green.xhtml?referer=&page=15 
• Common Poorwill: https://en.wikipedia.org/wiki/Common_poorwill
• Zugunruhe: https://en.wikipedia.org/wiki/Zugunruhe
• Pfeilstorch: https://en.wikipedia.org/wiki/Pfeilstorch
• Hans Mortensen: https://en.wikipedia.org/wiki/Hans_Christian_Cornelius_Mortensen
• Herodotus and crocodiles: https://books.google.com.au/books?id=_whgJIh_u9gC&lpg=PP1&pg=PA4&redir_esc=y#v=onepage&q&f=false

For a detailed history on the history of the science around avian hibernation I recommend Tim Birkhead's study The Wisdom of Birds.