Why did pastoral nomads of Jammu and Kashmir migrate?

(i) By the end of April, they began their northern march tor their summer grazing grounds.
(ii) Several households came together for this journey, forming what is known as Kafila. They crossed the Pir Panjal passes and entered the valley of Kashmir.
(iii) With the onset of summer, the snow melted and the mountain sides were lush green. The variety of grasses the sprouted, provided rich nutritious forage for the animal herds.
(iv) By the end of September the Bakarwals were on the move again, this time on their downward journey back to their winter base. When the high mountains were covered with snow, the herds were grazed in the low hills.