Tanzania, Jan. 28 -- Arusha. It is common to see the traditional livestock keepers moving from one part of the country or village to another.

The movements are more pronounced during the dry seasons, when there is a marked scarcity of water and forage for the animals.

But for the herders themselves, there is more than that. It is better known as "transhumance," a way of reaching out to better pastures at any particular time of the year.

It is one of the survival tactics of the nomadic herders, in particular, and has saved thousands of people and their animals from the severe impacts of unfavourable weather.

Again for the majority of Tanzanians unfavourable weather has much to do with prolonged or severe drought as experienced recently...