 Réunion swamphen

The Réunion swamphen ("Porphyrio caerulescens"), also known as the Réunion gallinule or (French for "blue bird"), is a hypothetical extinct species of rail from Réunion, Mascarenes only known from reports of travellers.Various 17th- and 18th-century visitors to Réunion reported blue birds, referred to in French as "oiseaux bleus".