In the more arid-living Grévy's zebras, adults have more fluid associations and adult males establish large territories, marked by dung piles, and monopolise the females that enter them. This species lives in habitats with sparser resources and standing water and grazing areas may be separated. Groups of lactating females are able to remain in groups with nonlactating ones and usually gather at foraging areas. The most dominant males establish territories near watering holes, where more sexually receptive females gather. Subdominants have territories farther away, near foraging areas. Mares may wander through several territories but remain in one when they have young. Staying in a territory offers a female protection from harassment by outside males, as well as access to a renewable resource.