Long have I debated wether this Divine Bird is an eagle or a condor. Few people here have convince me that it was an eagle, certainly Gwok Jing's pair of birds were in fact eagles but nevertheless I still remain skeptical about YG's bird. But I cast aside my doubts and conceited it was an eagle, mainly because I also like it to be an eagle as well. But after rereading the novel again, coming across that very passage that describe the Divine Bird, I don't see how it could be an eagle. I compare the description giving by JY with different species of birds and in fact the condor would fit it perfectly. Read the excerpt of the description from the novel below and draw your conclusion from it.
Here is the passage: (note: term bird was added to allow ambiguity)
Right in front of Yang Guo’s eyes stood a giant bird. Taller than a human, yet uglier even than one’s wildest imagination. Sparse feathers covered the bird’s entire body as if most of its feathers had been pulled off by somebody. The feathers were of a darkish yellow color, which made the bird appear dirty. It did look somewhat similar to the two eagles on Peach-Blossom Island, but its ugliness made the difference as vast as from heaven to earth. The giant bird had a hooked beak, and the big lump of skin, as red as blood, occupied the top of its head. There were probably thousands of bird species in the world, but Yang Guo had never seen any bird of prey as imposing and grand as this one. The bird strode about in big steps with its two extremely thick legs. Sometimes it would extend its two short wings, so short that one would wonder if the bird was capable of flying. But the way it walked, with its head held high, certainly showed great power and grandeur.
Notice the bolded description of this bird. It was ugly and had no feathers on the top of his head but red batches of skin, indication it was in fact a type of vulture. Even the passage was implying it was not the same species as the eagles of GJ, but a totally different type of bird.
So what type of vulture is it? So I did some research on vultures in asia, and come across they do exist there but these species of vultures known as Old World vultures aren't as ugly as the one describe. Here is a picture of Asia vulture:
Now look at the condor. It's so ugly!
But still condor doesn't live in Asia, but the Divine Condor is no ordinary condor, he could have travel there.
So with that, I conclude, the Divine Bird is definitely not an eagle but either a vulture or a condor. Imo, a condor is more fitting base on the description.