Did an ostrich pull off its own head? In _The Runaway Brain_ by Christopher Wills, the author illustrates the fact that ostriches aren't too bright by saying that an ostrich has been recorded as getting tangled in the fork of a tree, panicking, and pulling off its own head. Is there any evidence to back this up? Is it even plausible?

Yes.

A Reddit user has posted an unsourced video showing an ostrich with its head stuck in a fence. It forcefully tries to pull itself free, and decapitates itself on the fence, leaving its body convulsing.

Warning: This video shows the violent death of a bird, and may be disturbing.

NSFW Reddit page with video