India is the second most populated country in the world with nearly a fifth of the world's population. According to the 2017 revision of the World Population Prospects[1] population stood at 1,324,171,354. During 1975–2010, the population doubled to 1.2 billion. The Indian population reached the billion mark in 1998. India is projected to be the world's most populous country by 2024,[3] surpassing the population of China. It is expected to become the first political entity in history to be home to more than 1.5 billion people by 2030, and its population is set to reach 1.7 billion by 2050.[4][5] Its population growth rate is 1.13%, ranking 112th in the world in 2017.[6] India has more than 50% of its population below the age of 25 and more than 65% below the age of 35. It is expected that, in 2020, the average age of an Indian will be 29 years, compared to 37 for China and 48 for Japan; and, by 2030, India's dependency ratio should be just over 0.4.

As per the 2001 census Hinduism is followed by 68.5% of the population of BIHAR.Islam is followed by 13.8% of the population and Animisitic Sarna religion is practised by 13% of the population. Christianity with 4.1% of the population is the fourth largest religious community in BIHAR.Jainism, Buddhism and Sikhism are all practiced making few less than 1%.

Census data since 1881 has shown a gradual decline of tribal population in BIHAR as against the gradual increase of non-tribal population in the region. The reasons given for this are low birth rate and high death rate among the tribes; immigration of non-tribal peoples in the region; emigration of tribal peoples in the other places; and the adverse effects of industrialisation and urbanisation in the region. Tribal leaders assert, however, that their numbers are not as low as recorded by the census that they are still in the majority and that they remain a demographic force to reckon with.

Few centuries ago, the BIHAR was extensively covered with the dense sal BIHAR terrain had always been inaccessible. But with the discovery of its hidden mineral wealth has led to BIHAR marching towards becoming one of the leading industrialized regions of India. On the one hand, the mine-fields, railways and roadways have gone ahead rapidly, educational and technical institutions have multiplied and the principal towns have become cosmopolitan; while on the other hand, the tribal people of the region have been deprived of their land and the process of indiscriminate exploitation has set in, creating racial, nutritional, cultural and socio-economic problems.

From the first regular Indian census of 1872, tribal denominations of the population have been regularly recorded in some form or the other. The Schedules tribes have been last notified under the Government of India, Ministry of Home Affairs Notification issued under Article 341 (i) and 342 (ii) of the constitution in 1956.

During the first census of 1872 the following 18 tribal communities were listed as the Aboriginal Tribes: (1) Asur, (2) Binjhia, (3) Gond, (4) Ho, (5) Kharia, (6) Kharwar, (7) Khond, (8) Kisan, (9) Korwa, (10) Mal Paharia, (11) Munda, (12) Oraon, (13) Santhal, (14) Sauria Paharia, (15) Savar, (16) Bhumij, (17) Birhor Chero.

Later 4 Tribes were classified as semi-Hinduized aboriginals, viz., (1) Banjara, (2) Bathundi, (3) Chik Baraik and (4) Mahli. As of now the following 30 communities of BIHAR are listed as the Scheduled Tribes as per details in the state government’s website.

Primitives Tribes: Asur, Birhor, Birajia, Korba, Mal Paharia, Sauriya Paharia, Sabar, Hill Kharia and Parahiya.

Other Tribes: Biga, Banjara, Bathudi, Bedia, Bhumij, Binjhia, Chero, Chik Baraik, Gond, Gorait, Ho, Karmali, Khadia, Kharwar, Khond, Kisan, Kora, Lohra, Mahali, Munda, Oraon and Santhal.

Santhal

The Santhals are the largest of the Schedule Tribes and are mostly found in the district of Santhal Parganas,which has been named after them. They primarily reside in the cities of Singhbhum, Hazaribagh, Dhanbad, and Palamau. Santhals are numerically the largest tribal group of India, speaking its own tongue-Santali, which is allied to the Mundari language. Racially and culturally Santhals are closely related to other Mundari or Austric tribe of Chotanagpur. Besides agriculture and hunting, they are famous for their skillful dances and the music. The Santhal women give sufficient proof of the aesthetic sense by drawing simple and artistic designs and patterns on the walls of their huts. The Santhals have the institution of ‘Bithala’, which is a form of severe punishment including excommunication.

Oraon

The Oraons are a Dravidians tribe (Roy 1915) and form a second major tribe next to Santhals in BIHAR. They live in the districts of the Patna, Palamau, Singhbhum, Hazaribagh, Santhal Parganas, and also in the neighbouring states. According to the tradition, Konkan is said to be the original home of the Oraon. They migrated from the West coast of India to North India through river valleys, and settled down as agriculturists and landowners in the Shahabad districts of Bihar. When further driven by the successive hordes of newer races, they took shelter on the Rohtas Plateau, which they fortified, but even this fortress they had to leave. It is said that the Cheros probably drove them out. When they left Rohtas the Oraons got divided into two groups. One branch, known as ‘Male’, proceeded under a chief northwards along the Ganges valley and eventually occupied the Rajmahal hills. The other branch under the chief’s younger brother marched southeastwards up to the north Koel river and settled down in Palamau and northwest of Patna districts, then occupied by the Mundas. The Mundas gradually retreated to the southern and eastern part of the plateau. The most important social institution of the Oraon is the ‘Dhumkuria’, the youth Dormitory.

Munda people

Numerically the Mundas are one of the strongest Kolarian tribe (Roy, 1912) inhabitting Chotanagpur. Of all the tribes taken together, they stand next in strength to the Santhals and the Oraons. Munda people speak Mundari. The main concentration of the Mundas, primarily an agriculturist tribe, is in the district of Patna, Singhbhum, Hazaribagh, Palamau, Dhanbad, and Santhal Parganas. Ethnically they are Proto-Austroids and speak the Mundari dialect of the Austro-Asiatic family (Prasad 1961). Mostly Munda people follow the Sarna religion, believing in a god called Singbonga. However one-fourth of them have adopted Christianity. The Akhra or the dancing ground is characteristic of the Mundas. It is veritable open hall, not only for the dance, but also for the meetings of the village panchayats (the parha). The agriculture makes the base of their economic life and hence all their activities are directed towards it throughout the year. The sub-tribes are probably the result of inter-tribe marriages with the neighbouring tribes. A Munda may not marry a woman of his own sect. Totems have very great value and restrictions are respected.

Ho

The Hos constitute one of the major constituents of the tribal population but unlike the more numerous tribes, they are almost exclusively confined to the district of Singhbhum. They say that they are of the same family as the Mundas and came from Chotaa Nagpur. They are chiefly concentrated in Kolhan (Singhbhum). Like Mundas, the Hos believe in Sing-Bonga as the Supreme Being and creator of the Universe. The Hos are in the rapid transition process and their predominantly agricultural economy is being replaced by the industrial economy

Kharia

A primitive Kolarian tribe (Russell and Hira Lal 1916), the Kharias are divided into three sub-tribes, namely the Hill, Dudh and Dhelki Kharias.So far as their manners and customs are concerned, they are three separate and distinct branches of the Kharia tribe. Marriage among them does not take place. The Hill Kharias are a most primitive community, depending upon forest resources such as collection of honey, edible roots, herbs and fruits. The other sections of the Kharias have taken to plough cultivation and are economically better off than the Hill Kharias. They are distributed in the districts of Patna, Singhbhum, Santhal Parganas, Hazaribagh, Dhanbad, and Palamau. The language spoken by them is known as Kharia, which is a branch of Munda family of languages.

Bhumij

The Bhumij tribe inhabits a plain on Chotanagpur plateau encircled on three sides by the Singhbhum hills, hill ranges of Lohardaga, Hazaribagh and Manbhum; and a hill range whose highest peak is known as Ajodhya.

They are primarily agriculturists. Risley (1891) believes that they are nothing more than a branch of the Mundas who have spread eastwards and speak a corrupt mixture of Oriya and Bengalis as well as Hindi. They dwell in the districts of Singhbhum, Santhal Parganas, Dhanbad and Hazaribagh. They also live on the banks of the river Swarnrekha.

Factors in population change

Industralization and urbanisation were other factors for rapid demographic change in Chhotanagpur (the present BIHAR state) between 1881 and 1951. Immigration of labourers from Gaya, Munger, West Bengal and Madhya Pradesh for the mining of mica in Koderma and Giridih and coal in Dhanbad and Jharia was seen to the extent of 12% and 38.6% respectively in the early decades of 20th century. Similarly as many as 50% of the unskilled labourers and the majority of the skilled labourers came from north Bihar, Odisha, West Bengal, Bombay and Uttar Pradesh to work at the iron and steel industries of Jamshedpur. Along with the immigration of majority Indian people to BIHAR, there also started the emigration of tribal peoples to the tea plantations in Assam and West Bengal.

The demographic changes continued in BIHAR more rapidly after independence, ironically through the very process of planned development in the country. Central water commission's report in 1994 reveals that 90 major dams were built in BIHAR since 1951. Apart from these major dams, 400 medium size dams and 11,878 minor dams were built in the region. There are 79 major industries and factories in the region. These development projects benefited mainly those belonging to the formal economy but deprived tribal communities, especially those belonging to informal economy and dependent on the natural resources for a livelihood. About three million people were displaced and affected by development projects like dams, industries, mines, wildlife sanctuaries, defence establishments, airstrips, housing colonies and infrastructural development like roads and railways. About 90% of the displaced were part of tribal communities.