Migratory birds are those which move northward in the spring and southward in the fall because of changes in the weather. With its moderate temperature, Taiwan is one of their stopovers and winter shelters. To encourage our people to treasure this natural resource, and in conjunction with the Second East-Asian Bird Protection Conference, this Directorate released a set of two stamps on October 8, 1983, the opening day of the Conference. 　　The stamps take as their main designs two migratory birds-Lanius cristatus and Butastur indicus, which travel south from Siberia through the northeastern provinces of China mainland, Korea, Japan, and the southern part of Taiwan in September and October of every year.