“人为财死，鸟为食亡”，是旧时俗语。本义是“人为了追求金钱，连生命都可以不要。鸟为了争夺食物，宁可失去生命”，引申义为“生物在难以保全自身生命的情况下会用尽全力去尝试加以保全，以至于不择手段。”

lit. human beings will die for riches, just as birds will for food (idiom); fig. man will do anything in his means to become rich