At this time of the year bears should be fattening up for the winter. Yet they gather in some numbers on these apparently barren slopes. They're searching for a rather unusual food - moths. Millions have flown up here to escape the heat of the lowlands and they're now roosting among the rocks. Moths may seem a meagre meal for a bear, but their bodies are rich in fat and can make all the difference in a bear's annual struggle for survival. Another battle is being waged here but on a much longer timescale. These loose boulders are the mountain's crumbling bones. The Rockies are no longer rising but slowly disintegrating. All mountains everywhere are being worn down by frost, snow and ice.


在这个季节，熊类应该育肥长膘，为冬天储存脂肪，但是却有数量不少的灰熊聚集在这些似乎没有任何生物的山坡上。原来它们是在寻找一种不同寻常的食物。飞蛾！无数只飞蛾了躲避低处的炎热飞到了这里，聚集在岩石上。对熊而言，飞蛾算不上美食，但是飞蛾体内却含有丰富的脂肪，有了它们，灰熊每年的生存压力就会大大减轻。 这里还有另一场战斗正在进行，但时间更为漫长。这些松动的大漂石是山体破碎的结果。落基山脉已经不再上升，相反，它在慢慢解体。所有的山峰，无论在哪儿，都会受到冰雪风霜的侵蚀。