Wirö language
Wirö is an indigenous language of Colombia and Venezuela. It is attested only by a list of 38 words collected ca. 1900, but this is enough to show it is closely related to Piaroa, perhaps even a dialect. Speakers of the two understand each other, but not reliably, and consider them to be distinct languages.
Loukotka reports it as being spoken on the Ventuari River and Cunucunuma River.
Maco is not a proper name but a label applied by Arawakan speakers for unintelligible languages. In the case of Wirö, the following forms are found in the literature: Maco, Mako, Maku, Makú, Sáliba-Maco, and Maco-Piaroa, the latter also for the combination of Wirö and Piaroa.