Birjia tribes throng in the heartland in each and every corner of the Bihar state. Since these places comprise of lots of forests and valleys, it is only natural that these Birjia tribes are largely dependant on several natural resources of the forests. Agriculture is not at all suitable to carry on for maintaining their livelihood. As a recent phenomenon, many of these Birjia tribes have migrated to the plains and have settled down in the villages. Even these Birjia tribes have also got hold of some of the lands on which they exercise plough cultivation.
What is interesting is that the style of making the houses of Birjia tribes depends on whether they are built in plains or on the hilltops. As per the record of the anthropologists, Birjia villages have less number of families. There are common features of all these Birjia houses. They set up houses with various materials like bamboo, Wood, bushes mud, leaves, grasses, and tiles. These houses are triangular or rectangular in shape and without any window. There is a small gate for entrance and exit. The house door is again closed with a `tati`.
Just like most of the tribal communities of Indian subcontinent, the society of these Birjis tribes too follow the rules of patriarchy. Family is nuclear with father or any other males as the head of any Birjia family. Family members constitute of father mother and unmarried children. However, married children make a separate house with the family of his husband and children. Marriage also holds the position of one of the important institutions of the Birjia society. Monogamy is prevalent, though in certain cases, both the bigamy and lrigamy occur. Widow re-marriages are in vogue amongst the Birjia tribes.
It is interesting to know that both these Birjia tribes equally celebrate the birth of both females and males. Ancestors also are worshiped on several occasions for the sake of place and prosperity of the Birjia family.
The economy of the Birjia community is basically based on agriculture. Since the earliest time, they have been the collectors of forest and food materials. As far as the occupations of these Birjia tribes are concerned, the tribes are mainly farmers. Apart from agriculture, gathering, hunting, fishing, basketry, working as labor on daily wages etc also contribute to the economic affluences of these Birjia tribal communities. Some of them go outside the villages for earning money. In the ancient period, instances have been cited which prove that many of these Birjia tribes collect food materials from the forest and that too in quite a large amount.
Following the trends of so many tribal communities of Indian subcontinent, these Birjia communities are spiritual and religious minded. They too have faith in the power and ecstasy of several deities. Sigi Devata, Mahadev-Parvati, Daraha, Marai Jevala, Indra, Baghaut, Agni, Snake etc are the deities of the Birjia. Also the ancestral spirit is being worshipped. Severa is a religious festival and is feted in great vivacity. They also worship some symbolic representations.