Piling bone

The tops of pilings are fairly inaccessible places for anything but a bird. But, birds really like them. A piling provides a good perch for hunting, and a spot inaccessible to land predators. Atop pilings I have seen: kingfishers, eagles, ospreys, flickers, gulls (ring-billed and herring), tree swallows, violet-green swallows, herons, geese, mergansers, ravens, starlings and merlins.

What I hadn’t seen before last month was a bone. On February 20^th, a bone appeared atop a rather tall piling in the Lake (first picture); a day later, it vanished.

Today (March 8^th) another bone appeared atop the same piling (second picture). Will it also leave soon?

The bone on the piling offers a whodunit?

I think that the best guess so far was offered by Ralph Ritcey of Kamloops when the first one appeared:

I would agree that the object is a piece of bone – most probably a section of long bone from a beef cut by a butcher and sold as dog food. You don’t mention ravens visiting the pilings but they, along with eagles, are the most likely suspects to carry a remnant from butchering and deposit it there.

My vote goes to ravens.

But, why would ravens do this?

The piling bone of February 20^th.

That bone vanished within a day and then a different bone appeared atop the same piling on March 8^th.