Blue tits and great tits don’t need to taste unpleasant foods to avoid them – they can learn not to try them by seeing another bird’s disgusted response, even if it’s only on video
Source:
https://www.newscientist.com/article/2234640-blue-tits-learn-to-avoid-gross-food-by-watching-videos-of-other-birds/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home