Purple gallinules courting (Porphyrio martinica)

These two purple gallinules faced each other from about 15 feet away, necks and heads up, and walked towards each other slowly until they were face to face...the female on the left then lowered her neck and head almost to the ground, while the male stayed upright...and finally the female turned around and offered her back to the male, keeping her head and neck down. He waited 10-15 more seconds looking at her back before he accepted the offer and mating ensued.