those are lovely stamps. So delicate.
I do like this set, I wish they had been issued as a commemorative sheet, though, as they would look good in a larger size.
The blue birds stamp I think introguing: are they doves, or crows, or other birds. And sorry, I can't help to see a molar in the figure between them, I would love to send it to Christophe Blaise, the mail art dentist in France...
I think they are not supposed to be any specific bird, but they do remind me more of doves on the orange and purple stamps, and a crow on the fuchsia stamp. There is a stamp in this set with hummingbirds on that Eva showed on her blog. http://mailadventures.blogspot.com/2016/10/birds-on-stamp.html