A bird in the foot is worth two in the hand

There is a bird's foot lying on the pavement outside my house. It has been there several weeks. At first I thought it was a twig. Every time I walked past I would look at it from the corner of my eye and eventually I agreed with myself it was a foot.
Sometimes I find it a little further along the street in one direction or another, but it is always within a few metres of the spot where I first saw it, months ago. I expect this is because it was kicked into a new position, although I concede it might have walked.

A lot of people walk past it every day, and none of them have kicked it into the gutter, picked it up to throw it into the bin, or buried it.

It does not appear to be decomposing.
It does seem to get thinner. Whiter.

Where is the rest of the bird?