As more parks and high-rise buildings started to appear, the monkeys started a retreat into the mountains, from which they would never return.
高雄壽山原名猴山；墾丁公園有座猴崖；宜蘭也有個「猴洞」，可見當時「人猴融洽」的昇平景況。但人類為追求更大的活動空間，漸將樹林夷為平地、山區闢為觀光地，獼猴棲息地也遭破壞，它們只有往更高、更深的山區遷徙。