It's a Word in the Guarani language. It is a way of calling in Guarani the Iribú, parao or Iribuacabiray. It is a variety of vulture or zopilote, which is located in the Chaco area.
acabiray-refers to a vulture spit with dark brown plumage, whitish wings and tail-
ACABIRAY: A species of vulture in the Argentina of dark brown.