Patagonian Desert albeit to the west, where precipitation is higher, bushes are replaced by grasses. Topographically the deserts consist of alternating tablelands and massifs dissected by river valleys and canyons. The more western parts of the steppe host lakes of glacial origin and grades into barren mountains or cold temperate forests along valleys. Inhabited by hunter-gatherers since Pre-Hispanic times, the desert faced migration in the 19th century of Mapuches, Chileans, Argentines, Welsh, and other European peoples, transforming it from a conflictive borderland zone to an integral part of Argentina, with cattle, sheep and horse husbandry being the primary land uses. The Patagonian
Patagonian grasslands The region holds very diverse fauna. Mammals include Patagonian mara ("Dolichotis patagonum"), southern viscacha ("Lagidium viscacia"), Wolffsohn's viscacha ("Lagidium wolffsohni"), Patagonian weasel ("Lyncodon patagonicus"), Humboldt's hog-nosed skunk ("Conepatus humboldtii"), cougar ("Puma concolor"), Falkland Islands wolf ("Dusicyon australis") and guanaco ("Lama guanicoe"). Threatened species include Patagonian mara ("Dolichotis patagonum"), guanaco, South American gray fox ("Lycalopex griseus") and South American fur seal ("Arctocephalus australis"). Bird include Darwin's rhea ("Rhea pennata"), Patagonian tinamou ("Tinamotis ingoufi"), black-chested buzzard-eagle ("Geranoaetus melanoleucus"), peregrine falcon ("Falco peregrinus"), band-winged nightjar ("Systellura longirostris"), Patagonian mockingbird ("Mimus patagonicus") and Patagonian yellow finch ("Sicalis lebruni"). Endemic birds found north of the