Самці фрегатних птахів надувають червоний міх під дзьобом щоб привабити самку

Frigatebirds perform an elaborate ritual when courting. Males inflate a large red pouch under their beaks called a gular sac.

They inflate their pouch, rattle their bill, and drum against the pouch while sitting on tree branches, watching eligible females flying by.

Once a female chooses a potential mate, she will land beside him, and the pair perform an elaborate head and neck dance.

National Geographic