Casimir/a definitely, and I would also use [name_m]Cosmas[/name_m] and [name_f]Morta[/name_f]! Those are the only ones I would actually use, I think out of the rest of the list Arturas, [name_u]Meadowlark[/name_u] and Songbird sound nice (one of my favs [name_f]Mavis[/name_f] means songbird)
I wouldn’t be brave enough to use any of them, but I think the following are usable, especially as middles: Songbird, [name_u]Meadowlark[/name_u], [name_f]Morning[/name_f] (alone, but not [name_f]Morning[/name_f] Dew), [name_m]Casimir[/name_m], Arturas, [name_f]Morta[/name_f], [name_m]Cosmas[/name_m]
They’re not for everyone, but I definitely would - and have! [name_f]My[/name_f] kids’ second middle names are in this category, and I absolutely love it everytime I say their name (we use first and middle names fairly often in my house).
Birdsong and Songbird would 100% be on my list for a middle for my fourth baby, but my last name is a type of bird so unfortunately they have to stay off the list. They have such lovely imagery though, I adore those names!