See how often they participate in the script: HERE.
Character Story: Falbi runs a flight by cucco game on the edge of Lake Hylia. By grabbing the legs of the cucco, Link can guide it to small platforms in the lake and make money.
Race Story: Humans typically live peacefully with other races throughout all of Hyrule. The more specific Hylian race is a subcategory of humans. They can be differentiated by their ears -- Humans have rounded ears and Hylians have pointed ears.