left behind

Picky eaters. We all know them. Items can't mix, no hot sauce, no offal. 

Impressive is that picky eaters exist in the animal kingdom as well. If a bird is outside of the pen overnight for any reason (usually they find a gap because of an uneven spot in the ground) it is a given that the next morning something will happen to them. 

This, the remains, is a new one. Google what leaves just the intestines of a bird and there is not an answer. 

It is impressive in terms of how much of the bird was consumed, and what was left behind. Whatever ate was an incredibly selective creature, to leave just this pile and not one other part of the bird.