Tzipporah nn Tzipi doesn't feel terrible serious to me. The Z spelling is more common in English, but I like that the Tz version is more accurate to how it sounds. It doesn't seem particularly serious to me.
Tzvi (
Zvi if you like the Z spellings better) would be pretty matchy. Yonah/Jonah would keep with the language family and bird meaning.
Colombo would also work with the bird meaning and
Robin even more obviously so.