To provide a bird injury prevention tool capable of easily passing a space between one set of edge lines.SOLUTION: A bird injury prevention tool 10 comprises: a main shaft member 11 extending straightly； branch rods 13 which form a pair being coupled to the main shaft member 11 rotatably, through a branch member 12 being continuous to an axial direction of the main shaft member 11； and a bone reception member whose one end part is rotatably coupled to an intermediate part of the branch rod 13 and the other end part is rotatably coupled to an outer peripheral part of a movement member 15, in which the bird injury prevention tool is formed into a skeleton of an umbrella. In a state in which the movement member 15 is moved toward one end part side of the main shaft member 11, a virtual circumference Cv coupling tip end edges of the branch rods 13, 13 forming a pair is extended, and in a state in which the movement member 15 is moved toward the other end part side of the main shaft member 11, the virtual circumference Cv coupling tip end edges of the branch rods 13, 13 forming a pair is shrunk.SELECTED DRAWING: Figure 1【課題】一組の縁線の間を容易に通過できる鳥害防止具を提供する。【解決手段】鳥害防止具１０は、真直に延びる主軸部材１１、主軸部材１１の軸方向に連設した分岐部材１２を介して、主軸部材１１と回動自在に連結した対を成す枝棒１３、及び、一端部を枝棒１３の中間部と回動自在に連結し、他端部を移動部材１５の外周部に回動自在に連結した受骨部材で、傘の骨組み状に構成している。移動部材１５が主軸部材１１の一端部側に向かって移動した状態では、対を成す枝棒１３・１３の先端縁を結ぶ仮想の円周Ｃｖを拡径し、移動部材１５が主軸部材１１の他端部側に向かって移動した状態では、対を成す枝棒１３・１３の先端縁を結ぶ仮想の円周Ｃｖを縮径できる。【選択図】図１
