The forests hold a deep attraction for Sun. After researching bird communities for a while, he wanted to try his hand at researching individual bird species, so he found a mentor at Texas A & M University.
對森林充滿憧憬的他，從事鳥類社會研究一段時日後，又想嘗試單一鳥種研究，就在美國德州農工大學找到指導教授。