In Brazil, the genus Procnias is known by its indigenous name 'araponga', so the author of the Esperanto Wikipedia article named it 'arapongo' (1), apparently following the Portuguese Wikipedia page.

def.fontoj.net (2) (biological terminology in German, Latin and Esperanto) notes 'arapongo' but prefers 'proknio', so Procnias albus is 'blanka proknio'. Since we usually follow the Latin when naming plants and animals, it seems 'proknio' is the way to go.

(1) https://eo.wikipedia.org/wiki/Arapongo (2) http://def.fontoj.net/Voegel.html (enter procnias next to Suchbegriff and click Finden)

In Brazil, the genus Procnias is known by its indigenous name 'araponga', so the author of the Esperanto Wikipedia article named it 'arapongo' (1), apparently following the Portuguese Wikipedia page.

def.fontoj.net (2) (biological terminology in German, Latin and Esperanto) notes 'arapongo' but prefers 'proknio', so Procnias albus is 'blanka proknio'. Since we usually follow the Latin when naming plants and animals, it seems 'proknio' is the way to go.

(1) https://eo.wikipedia.org/wiki/Arapongo 
(2) http://def.fontoj.net/Voegel.html (enter procnias next to Suchbegriff and click Finden)