How beta-skeletons lose their edges

A {\beta}-skeleton is a proximity graphs with node neighbourhood defined by continuous-valued parameter {\beta}. Two nodes in a {\beta}-skeleton are connected by an edge if their lune-based neighbourhood contains no other nodes. With increase of {\beta} some edges a skeleton are disappear. We study how a number of edges in {\beta}-skeleton depends on {\beta}. We speculate how this dependence can be used to discriminate between random and non-random planar sets. We also analyse stability of {\beta}-skeletons and their sensitivity to perturbations.