I have used Zebrawood for duck calls for a while now. It's very open grained, and it will split easily from the endgrain. It also has a smell that is not the most pleasant (very close to a dirty diaper) when it's cut or power sanded.
If you're looking for something out of the norm that will make a great handle, I'd mabey suggest Persimmon or Osage Orange. Both are hard a rock and will take a ton of abuse well. You can find either fairly easily in 12" to 18" lengths.
Good luck,
Bob