Indigenous hunting and its impact on wildlife represents one of the most critical and controversial issues in Taiwan. This study aims to investigate the interplay between governmental conservation institutions and indigenous hunting norms in an anonymous Truku area. The empirical results show that, over the long term between the 1970s and mid-2000s, socioeconomic change has played a pivotal role, and has exerted a relatively slow but significant influence on indigenous hunting norms, while governmental conservation institutions have played a minor role. In such external institutional settings, Truku hunting territory norms remain robust. However, since the mid-2000s, strict legal enforcement by governmental institutions has resulted in a more rapid decline in indigenous hunting territories. In the long run, wildlife populations have significantly recovered. At the same time, indigenous hunting activities have dramatically declined, and nowadays indigenous hunting norms are increasingly losing their influence. Finally, we discuss the normative implications of the empirical findings. We suggest that, in friendly external institutional settings, Truku hunting territory norms are quite robust. Accordingly, in cooperating with the future framework of Truku self-governance, a wildlife co-management proposal governed by both the governmental conservation institutions and Truku hunting norms may become feasible.