The Meerkats live in the red part of the map(Image 4), the Kalahari Desert.
Arda map
After looking at the Arda map I found that the meerkats have a very small place to live in the desert. They live west of the Hiler Lands on a stretch of land stretching out on the east side of the continent. They used to have a huge section of land south of the Hiler Lands, however over a time span of 10 million years the environment changed giving the meerkats a narrow but long place to live.
The dessert the meerkats lived in 10 million years ago have very little mountains form the Grey Mountains meaning that the landscape was mainly flat with a few hills. Now, majority if not all the land the meerkats live on now is the Grey Mountains and hills. Being in the desert the climate is very warm and dry, just like their environment before.
The continent the meerkats have lived on has gotten smaller over the years. The Grey Mountains are now on the west side of the continent when years ago the mountains were in the middle of the continent. Even though the meerkats migrated to the east the prey and predators are still the same. With the exception of the animals that live on the Grey Mountains like foxes, lynxes, bears, minks, squirrels, and wolves along with a few animals that did not move with the rest of the group that could be a threat to the meerkats in their new home. However, those animals soon died due to the new harsh environments of the desert. Also, some of the meerkats died before moving to the new environment because they were not used to living in the environment that their first home had become(Grasslands and the Deciduous Forest).