Bird - Analysis of how a gull wing folds and extends

In this video I try to analyse the functional anatomy of a gull wing. I am particularly interested in how the bones orientate themselves within the wing as it articulates, focussing on the elbow joint as it relates to a human. I show how a wind does from a relative plane when extended to a body hugging wing when closed. FYI. I found this unfortunate dead juvenile gull on the side of a cycle path. I suspect it broke its neck after accidentally flying into a mesh fence.