The kōkako make up two species of endangered forest birds which are endemic to New Zealand, the North Island kōkako (Callaeas wilsoni) and the presumably extinct (recently data deficient) South Island kōkako (Callaeas cinereus). They are both slate-grey with wattles and have black masks. They belong to a genus containing five known species of New Zealand wattlebird, the other three being two species of tieke (saddleback) and the extinct huia. Previously widespread, kōkako populations throughout New Zealand have been decimated by the predations of mammalian invasive species such as possums, stoats, cats and rats, and their range has contracted significantly. In the past this bird was called the New Zealand crow: it is not a crow at all, but it looks like one from a distance. The spelling kokako (without a macron) is common in New Zealand English.