the most known environment of the archipelago is its laurel forest (laurisilva) which still extends over 15,000 hectares or 20% of the archipelago. these forests, very rich in biodiversity, are the largest and best-preserved laurel forests in the entire macaronesia region. they are home to unique plant and animal species, including the famous trocaz pigeon or madeira laurel pigeon ("columba trocaz"), and the madeira kinglet ("regulus madeirensis"). the most threatened bird of europe, the madeiran or zino’s petrel ("pterodroma madeira") inhabits the highest cliffs in the central mountainous massif of the madeira island.