No Ythrian

In this image, we see the Ythrian's "...gill-like antlibranch slits...'biological superchargers'..."
-"Wingless," p. 300.

Remember that, on land, he stands on claws at the joints of his wings. The apparent, and indeed former, legs and feet, are now instead used as arms and hands.

"An Ythrian in flight burned more food and air than a human; they said he was more alive.
"But I am no Ythrian, Nat thought. Tears stung him. He wiped them away, angrily, with the back of a wrist, and sought the controls of his gravbelt.
"It encircled his coveralls at the waist. On his back were the two cylinders of its powerpack. He could rise, he could fly for hours. But how wretched a crutch this was!" (ibid.)

(If they are more alive when flying, then maybe this is what gives them the idea of God the Hunter.)

I try to keep quotations short. Otherwise, I could just wind up transcribing an entire Poul Anderson text. However, in this case, I had to keep going till I reached "...how wretched a crutch this was!" That is what Nat thinks. Of course he is going to learn better.

Generations later, Christopher Holm:

joins Stormgate Choth;
takes the Ythrian name, Arinnian;
speaks Anglic with an Ythrian intonation;
translates Planha works into Anglic;
contributes to the Earth Book;
is promiscuous with "orthohuman" women but expects "bird" women to emulate (what he sees as) Ythrian purity - a double standard;
argues that he is:

"...widening and purifying his humanity."
-Poul Anderson, The People Of The Wind IN Anderson, Rise Of The Terran Empire (Riverdale, NY, 2011), pp. 437-662 AT p. 438.

A far cry from Nat resenting that he is no Ythrian. Holm's contemporary, Tabitha Falkayn, is Hrill of Highsky Choth and calls herself "Ythrian" because Avalon is in the Domain of Ythri but she does not deny her humanity in the way that Holm effectively does despite his talk of widening and purifying.