You could try burying it. But take a little care about where and how long.
I found a seagull head on the beach last summer that still had most of the muscle and feather attached, with a really beautiful beak. I brought it home & buried him in my yard, about 8 inches deep. After 3 weeks or so I dug him back up and the skull bones were actually decaying and falling apart! Don't bones usually take forever to do that? I only have the beak and some skull bits left.
I buried it in a place where I'd sheet mulched and added lots of compost and compost tea, so I guess the soil in that area had loads and loads of scavenger-critters, to decay bone so quickly. Also, a bird skull just has such fragile, fine bones.
Penny Scout has some cool crow-feet earrings.