source image: NASA: https://www.jpl.nasa.gov/images/pia05557-its-a-bird-its-a-plane-its-a-spacecraft

Sounds:
different sources, mostly snippets of youtube films

The bird sounds you hear are all natural. No special effects or manipulations were used to create these sounds. The wild and domesticated birds you hear are really good imitators of the sounds they hear all around them; digital, human and mechanical. They include car alarms, smartphones, playgrounds, cameras and fax machines, among others.
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