This bird-specific postsynaptic neurotoxin irreversibly binds and inhibits the chick muscle alpha-1-beta-1-gamma-delta (CHRNA1-CHRNB1-CHRNG-CHNRD) nicotinic acetylcholine receptor (nAChR) 100-fold more compared with the mouse receptor. The weak binding to mouse receptor is reversible. Monomer. Expressed by the venom gland. Belongs to the snake three-finger toxin family. Ancestral subfamily. Boigatoxin sub-subfamily.