They smack beaks with others of their kind to communicate. The strength and number of hits tell each other how they feel.
#108
Sun & MoonNormal: $0.19
Reverse Holo: $0.45
#22
SM Trainer Kit LycanrocNormal: $0.38
#166
Lost ThunderNormal: $0.50
Reverse Holo: $0.87
#145
Vivid VoltageNormal: $0.18
Reverse Holo: $0.50
#68
Pitch BlackNormal: $0.13
Reverse Holo: $0.20
#94
Pitch BlackHolo: $1.42