The vegetation of the western United States is sparser and the flora of the virgin forests where researchers may find tree-dwelling raptors is less diverse than in Taiwan. Three years ago the American professor who was Sun Yuan-hsun's advisor on his master's program, imagining the environment in Taiwan to be similar to the United States, expressed the hope that Sun would find a few more nests in Taiwan to research.
同樣研究以大樹為家的猛禽，美國西部植被生長寬闊，原始林相單一，三年前，孫元勳的美籍碩士指導教授就以美國的環境想像台灣，希望孫元勳能在台灣多找幾個鳥巢做研究。