Was it this article?
Blue and Gold Macaws (Ara ararauna): Info and Photos
I'd be curious to see if any academic/scientific research has been done.
Looking at the criteria to recognise a subspecies:
"Members of one subspecies differ morphologically or by different coding sequences of DNA from members of other subspecies of the species. [...] two groups would interbreed freely provided only that some external barrier were removed (e.g. geographical location)"
If there is enough evidence, based on size, distribution and colour differences, or even different coding in the DNA, then the subspecies of
Ara ararauna or
Ara chloroptera may be recognised. That is if anyone has bothered to actually look though from a scientific standpoint.
Slightly related: I am interested in reading this paper, based on title alone:
- Google Scholar ( A new subspecies of scarlet macaw (Ara macao) and its status and conservation)