Why do herders often have to move their livestock in order to find the best grazing land?

Herders frequently move their livestock to find the best grazing land due to factors like seasonal variations, overgrazing, and resource availability. As grasslands can become depleted or dry up, herders must seek new pastures to ensure their animals have adequate food and water. This mobility helps maintain the health of the herd and the sustainability of the land. Additionally, climate conditions and competing land uses can further necessitate the relocation of livestock.