The festival of Si-Donyi is celebrated by one of the major tribes of Arunachal Pradesh known as Tagin. Celebrated in the month of January every year, this festival marks the beginning of a new year. The festival is observed for the well-being of the community and mankind as a whole. Tagins are the inhabitants of Upper Subansari and can also be found in West Siang district.
The term Si-Dyoni comes from two words ‘Si,’ which means earth; and ‘Dyoni,’ which means earth. So, evidently during the festival, the sun and earth are worshipped along with other deities and sacrifice of two Mithuns (Gayal) are conducted with the warding off of the evil spirit. The high priest, Nyibu recite certain hymns known as ‘Uyu Barman’ that calls the spirit who is responsible for causing the problem. Offering of a white chicken, which can be of any gender is made to ‘Nonyi’ on the peak of a high pole in a ceremony known as ‘Donyi Meli Pinam.’ Then sharing the meat of the sacrificed Mithun is done amongst the people. Also, rhythmic dances such as Chungne, Riabu, Takar Ghene and traditional folk dances like Konyi Bokar and Hoyi Penam are also performed in the celebration to please the Si Donyi.