The Maasai community lost their grazing lands because:
(i) Colonialism: European imperial powers' scramble for territorial possessions in Africa led to slicing up of the continent into different regions/colonies. Maasai land was divided between British Kenya and German Tanganyika. This restricted the movement of the Maasais between regions.
(ii) White settlements: The best grazing lands were taken over for white settle men and pastoralists were not allowed entry to these settlements and markets. This restricted not only grazing lands but prohibited them from entering into any form of trade as well. They were, moreover, pushed into a small area that was arid and poor in pastures.
(iii) Expansion of cultivation: In the late 19th-century local peasant communities were encouraged by the British colonizers to expand cultivation at the expense of pasture lands.
(iv) Setting up of reserves: Large areas of Maasai grazing lands were turned into game reserves, e.g. Samburu National Park in Kenya and Serengeti Park in Tanzania. These reserves were out of bound of the pastalists.
(v) Permits: For lands that were available special permits were required and rules were laid down. In case of default, Maasais were subjected to harassment and severely punished.

(i) (a) Climatic conditions: Climatic conditions are primarily responsible for the movement of the nomadic people. In winter, when the .high mountains are covered with snow, the nomadic pastoralists of the mountains move to the low hills. With the onset of summer, they start their backward journey. Example: Gaddi shepherds of Himachal Pradesh. In the plains and plateaus, the alteration of monsoon and dry season defines the seasonal rhythm of their movement. In the dry season, the nomads move to the coastal region to graze their cattle on the flourishing agricultural tract and rich oil. With the onset of the monsoon, they return with their flocks to their settlements on the plateau.
(b) Fodder: Grazing grounds, i.e. fodder for the animals is another factor that decides the movement of the nomads. The Gujjar Bakarwala of Jammu and Kashmir migrate to low hills of the Siwalik not only to avoid harsh winters but also due to the availability of grazing grounds in the low hills.
(c) Foodgrains: The availability of foodgrains in different regions is yet another important factor that decides their migration, e.g. the Dhangars get rice from Konkani peasants.
(d) Market: Nomadic tribes combine a range of different activities-herding trading and cultivation. Apart from climate and need for grazing pastures, their movement is partly influenced by need to sell plow, cattle and
goods to villagers.
(ii) The advantages to the environment from this continuous movement are:
(a) Continuous movement of the nomadic tribes allowed the pastures to recover. It prevents their overuse and intensive grazing, which would lead to the deterioration of pastures.
(b) Enabled pastoralists to set up relationships with farmers on the way so that the herds could graze on the stubble of the harvested field. This helped in weeding the soil of leftovers. The cattle also helped manure the soil. 
(c) Nomadic pastoralism provided a way out for supporting a population in a difficult environment and presented a sustainable approach to land use.

The Criminal Tribes Act was passed by the British government in 1871 to limit the movement of the nomadic people.
Features:
(i) By this Act, those who hawked their goods-traders, pastoralists, and craftsmen were classified as criminals by nature and birth
(ii) These communities were to live in notified village permit.
(iii) They were not allowed to move out without permit.
(v) Village police kept a continuous watch on them.

The British wanted to transform all forest lands which were actually grazing lands, into cultivated farms because,
(i) By expanding cultivation they sought to increase revenue collection as cultivated farms were main source of land revenue and finance.
(ii) This land could also be used to produce commercial crop like jute, cotton, and sugar whose demand was ever increasing in England due to rapid industrialization.
(iii) Colonial government regarded all forests which did not produce commercially viable timber as unproductive.

After the Partition of India, the new political boundaries stopped their (Raika's) movements into Sindh
(i) Raikas found new places to go. In recent years they migrated to Haryana.
(ii) They have set-up relationship with farmers on the way, where sheep can graze on agriculture fields after the harvest are cut. Their animals also help manure the field
(iii) They combined a range of activities-cultivation, trading, and herding to make their living

(i) During the monsoons they stayed in the central plateau of Maharashtra, which was a semi-arid region covered with throny scrub.
(ii) During October-November due to shortage of fodder, they moved to the Konkan where they were welcomed by peasants. Here their herds fed on the stubble of the Kharif harvest.
(iii) Dhangar flocks provided manure for the fields to be made ready for rabi harvest. Here they also got food grains from the locals.
(iv) With the onset of monsoon, they returned to their settlements on the dry plateau because the sheep could not tolerate the wet monsoon conditions

(i) The Gaddi Shepherds of Himachal Pradesh spent their winter on the low hills of the Siwalik ranges, grazing their flocks on the scrub forests
(ii) By April they moved north and spent the summer in Lahul and Spiti. When the snow melted and the high passes were clear many of them moved on to higher mountain meadows.
(iii) By September they began their journey.
(iv) On the way, they stopped once again in the villages of Lahul and Spiti reaping their summer harvest and sowing their winter crop
(v) Then they descended with their flock to the winter grazing grounds on the Siwalik Hills.
(vi) Next April once again they began their march with their goats and sheep to the summer meadows.

The Gujjar Bakarwals migrated to Jammu and Kashmir in the 19th century in search of pastures for their animals.
1. Winter: When the high mountains were covered with snow, and there was a lack of pastures at high altitudes, they moved to the low hills of the Siwalik. The dry Scrub forests here provide forage to their herds. By the end of April, they began their northern March for their summer grazing grounds.
2. Summer: With the onset of summer the snow melted and the mountainsides became lush green. By the end of September, the Bakarwals started their backward journey.

(i) Herds of goats and sheep
(ii) Or camels and cattle

Serengeti National Park - Tanzania.

Most of them are found in semi-arid grasslands and arid deserts where agriculture is difficult.

By the Grazing Act, the British levied tax on the pastoralists, on every animal they took to pastures to graze. It was hated by the impoverished pastoral community for it was contrary to their customary rights.

The Gujjar herders in winters came down to the dry forests of the 'bhabar' and in summers they went to the high meadows i.e.'thy bugyals'