PLANET EARTH Mountains

You might expect that grazers（食草动物） would avoid each other's patch but this is a special alliance from which both partners benefit. It's not so risky to put your head down if others are on the lookout. Ethiopian wolves - they won't attempt an attack in broad daylight.



But at dusk the plateau becomes a more dangerous place. With the grazing largely over there's a last chance to socialise before returning to the sleeping cliffs. An early warning system puts everyone on the alert. Their day ends as it began, safe on the steep cliffs.
The Ethiopian volcanoes are dormant（休眠的）, but elsewhere others still rage. Volcanoes form the backbone of the longest mountain chain on our planet - the Andes（安第斯山脉） of South America. This vast range stretches 5,000 miles from the Equator（赤道） down to the Antarctic. It formed as the floor of the Pacific Ocean slid beneath the South American continent, buckling its edge.



At the southern end stand the mountains of Patagonia（巴塔哥尼亚，地处南美）. It's high summer, but the Andes have the most unstable mountain weather on the planet and storms can erupt without warning. Temperatures plummet（骤然下降） and guanacos（产于南美安第斯山脉的骆马） and their newborn young must suddenly endure a blizzard. Truly, all seasons in one day.