This name definitely seems more suited for a female. This is just like another nature inspired bird name like Robin or Wren. This seems like a good name if that is your style.
I like Larkin for a boy and it sounds so masculine to me! For a girl, I prefer Larkine. I’m starting to understand that some boy names should be best on boys because Charlesine and Christophine seem pretty on girls, they’re never used! That makes no sense:):):):):):):))))))!
As a female with the first name of Larkin, I can honestly say I've never met anyone else -- male or female -- with the same name. In school I always looked at it as: "Well, even if I just sign my first name, the teacher won't confuse me with anyone else." :-).It is far more common as a last name though. Both it and my middle name (Dyer) were taken from the surnames of two maiden aunts.
I wouldn't name my kid this or anything, but it looks like a terrific name for a character in a fantasy book, and maybe even a good name for a band, if you think about it.