@realsimon@mastodon.green Oh yes, it's Henry. He does this frequently. When he sings properly, he opens his beak wide. However, this is him 'chatting', also known as subsong. It's very quiet. It's a bit of a mystery why they do this. Possibly, it's rehearsal for the main song, but they often throw in other elements that aren't in the main song, and it's more of a continuous warble. They tend to do it when they're relaxed.