You layer together rhythms really nicely. I like how the kalimba's percussive hit creates this like 16th note subdivision that lasts throughout the entire piece.
Automation is a must-have addition here, both to make your instruments more expressive and to make the moment where you take out all the instruments to only hear the birds singing that much more impactful. Imagine if at that point in the climax, you turn the reverb way up so it takes our ears to time to adjust and appreciate the bird songs.