Such was the situation I encountered when I stopped at a city park in a small Wisconsin town last weekend. I sat down on the grass next to a bubbling stream to eat a sandwich, then noticed a fluttering in the air above me. There, hanging vertically below the branch of a tree above the stream was a cedar waxwing, intermittently fluttering its wings.
At first I thought the bird was trapped in a spiderweb, but a moment's study revealed a nearly-invisible line extending above the bird to the branch. Apparently some fisherman had gotten a fly tangled in the tree and cut his/her line, leaving the lure (with its feathers) dangling above the water.
I was unable to reach the bird, having nothing longer with me than my trekking poles. I stopped two passersby, but none of us could bend or climb the tree. The hook appeared to be embedded in the bird's beak, and the bird would occasionally place a foot on it and try to pull himself up, but seemed unable to get a grip on the small lure.
I was just a half-hour from my house, so I returned home to get the longest tool available (here in the midwest, that item is a roof rake). My wife came with me on the return trip and brought a wire cutter and a needle-nosed pliers.
By the time we got back, the bird was gone, and only the hook remained. I hope this means the cedar waxwing was able to leverage himself off of the barb and fly away; we didn't find any evidence of a carcass in the underbrush, though he might have fallen into the water and washed downstream.
A cautionary tale for anglers. Perhaps some birders have seen similar situations, but it was a new one for me.