A lot of the bird calls were found on xenocanto: https://xenocanto.org/

The Cornell Lab also has a useful website where I found the raven sounds: https://www.allaboutbirds.org/news/

MER Lacey's thesis can be found here: https://discovery.ucl.ac.uk/id/eprint...

And Ramirez's is here, although I'm not sure whether it needs an institution login: https://ethos.bl.uk/OrderDetails.do?u...


_____

This channel's Patreon (thank you very much to anybody who has donated):

  / simonroper