An Ythrian

In Poul Anderson's The Day Of Their Return, 8, when Erannath arrives and introduces himself as from Stormgate choth on Avalon, we remember The Earth Book Of Stormgate and The People Of The Wind. All that we know of Avalon is in these two volumes although their contents are distributed through the first three volumes of The Technic Civilization Saga.

Despite all the information on Avalon, I have not yet tried to summarize a description of an Ythrian:

an Ythrian is graceful in the air but awkward on land;

he has a six-meter wingspan;

his legs are his folded wings;

his feet are claws where his wings bend;

rear-directed bones give support when standing;

height 135 centimeters;

mass 25 kilos;

arms, with hands evolved from talons, beneath keelbone;

three clawed fingers and two thumbs on each hand;

dewclaw on inner wrist;

mouth with lips and carnivore fangs;

unblinking gold eyes;

brown body plumage;

gill-like antilbranchs that pump oxygen into the blood when in flight;

wears an apron holding knife, canteen and pistol;

can live off the land but a wide area is necessary to support one Ythrian.