The shroud (received from a newbie quest), sais in it's description that it can be easily wrapped around a head of any shape or size... but can't be worn by an arial.

<100%hp 100%m 74%mv 1354tnl - 10 PM> get shroud sack
You get a fine gauzy burial shroud from a large sack.

<100%hp 100%m 81%mv 1354tnl - 11 PM> examine shroud
This light, gauzy burial shroud has been delicately woven with the finest
threads of spider silk, so that it is virtually transperent in its effect.
It has an airy beauty to it, and rests light in your hands. The cloth has
been woven into a shape that allows it to be easily wrapped around a head
of any shape or size.

A fine gauzy burial shroud is clothing worn on face, made of spidersilk, and weighs 0 pounds 1 ounces.

<100%hp 100%m 95%mv 1354tnl - 1 AM> wear shroud
That will not fit your avian features.