these commuters rely on their loud clicks to find their way through the cave passages in total darkness. 这些住客利用它们响亮的叫声 在漆黑一片的洞穴通道内辨别方向
Yet the nightly onslaught has little impact on bat numbers - 然而 每天傍晚的攻击只会 对蝙蝠数量产生很小的影响
so the bat hawks bolt their catches on the wing 于是蝠鹞一边飞一边吞下猎物
They're totally dependant on the digested remains of food that's brought here from outside. 它们完全依赖的食物消化残渣 都是来自于外界
which spend part of their day resting on cave walls. 它们一天大部分时间都呆在洞壁上
Caves are one of the few habitats on Earth not directly powered by sunlight. 洞穴是地球上少数几种 不直接依赖阳光的生态环境之一
In the absence of plants this food chain is based on a continuous supply of bat droppings. 在缺少植物的情况下 这里的食物链 完全依赖供应不断的蝙蝠粪便
The bats roost high on the walls and ceilings 这些蝙蝠倒挂在洞壁和天顶上