夏天的每个晚上，超过1500万只蝙蝠都会从圣安东尼奥市区外一个热烘烘的大地洞里出来。

　　They spiral up and out of the cave’s gapingmouth like a tornado and slowly gain elevation.

　　它们像龙卷风一样，从洞穴张开的大口盘旋而出，慢慢地越飞越高。

　　If you’re sitting nearby,you can feel the wind from their wings.

　　要是你坐在附近，就可以感觉到它们的翅膀扇出来的风。

　　Once the bats reach the treetops, they formcolumns that flow out and over the hills like plumes of smoke that appear tonever end.

　　这些蝙蝠一飞到树顶便成群结队，像缕缕烟雾一样，在丘陵间穿梭，仿佛永不止息。

　　It’s dinner time inTexas, and in the corn and cotton fields, the hairy, winged mammals will feaston moths throughout the night.

　　这是德克萨斯州的晚餐时间，而这些长着翅膀、毛茸茸的哺乳类动物也将在玉米地与棉田里整晚大啖飞蛾。

　　This bat emergence at Bracken Cave, home tothe world’s largest bat colony, requires an appointment, but it’s just oneof many nightly shows you can catch in Central Texas in July, August andSeptember.

　　布兰肯洞穴(Bracken Cave)栖居着世界上最大的蝙蝠群落；要观赏这里的蝙蝠一涌而出的奇观，需要事先预约。不过在德州中部，7、8、9月份，还有很多地方可以看到这样的夜间表演。

　　You can also see them at Old Tunnel StatePark, just south of Fredericksburg, or for a more urban experience, you canhave a picnic or cocktail and watch 1.5 million bats drop down from under theCongress Avenue Bridge in Austin and take off across the river like a school offish.

　　你也能在弗雷德里克斯堡南方的老隧道州立公园(Old Tunnel State Park)看到蝙蝠，或着来点都市风情，在奥斯汀来一场野餐或是品着鸡尾酒，一边观看150万只蝙蝠自国会大道桥下飘落又重新飞升，有如鱼群般横越河面。

　　They do this every night, but the best timeto catch them is when it’s hot and dry and they’re hungry, because that’s when they’ll head outearly.

　　它们每晚都会这么做，不过最佳观赏时机是天气又热又干、蝙蝠饿了的时候，因为它们在这种情况下会比较早出发。

　　The hotter and more uncomfortable you are,the better the bat flight, said Mylea Bayless, an ecologist for BatConservation International.

　　天气越热、人觉得越不舒服的时候，蝙蝠就飞得越好看，国际蝙蝠保育组织(Bat Conservation International)的生态学家麦莉亚?贝莱斯(Mylea Bayless)说。

　　As the saying goes, everything’s bigger inTexas, and the caves and bridges that these Mexican free-tailed bats call theirsummer home are no exception.

　　就像俗话说的，德州什么东西都比较大；这些墨西哥游离尾蝠(Mexican free-tailed bats)夏季栖身的山洞与桥梁也不例外。

　　The dome ceilings of large caverns —natural orconstructed —trap heat, making them the perfect temperature for females to roostand to raise their young.

　　不论是自然形成或人工建造，大型洞穴的圆拱顶部能留住热气，对想要找个栖息地、哺育幼兽的雌蝙蝠来说，这样的温度正好。

　　Warm, stable roosts like Bracken Cave are essentialbecause baby bats are born hairless and have only a few months to developbefore migrating to Mexico and Central and South America in the fall.

　　像布兰肯洞穴这类温暖又稳定的栖息地十分重要，因为蝙蝠宝宝出生的时候没有毛，它们在秋季迁往墨西哥与中南美洲之前，也只有短短数月时间生长发育。

　　These bat pups spend their energy ongrowth, not thermoregulation.

　　这些小家伙得把能量用来长身体，而不是拿来调节体温。

　　The millions of bats you see take off atonce in Texas are all females and babies.

　　在德州，你看到的那些同时起飞的百万蝙蝠大军，全都是雌兽与幼兽。

　　The males are around, but they’re scatteredabout in smaller caves or parking garages.

　　当地也有雄蝙蝠，不过它们分散在比较小的洞穴或车库里。

　　If it’s not the big Texancaverns, it’s the migrating corn earworm moths that bring the bats here everysummer.

　　除了德州的大山洞，迁徙的玉米穗夜蛾也是每年夏天吸引蝙蝠成群而至的原因。

　　A mother bat will consume about two-thirdsof her body weight in insects at night to meet her energy demands.

　　一只蝙蝠妈妈为了满足能量需求，会在夜间捕食大约相当于自己体重三分之二的昆虫。

　　Economists estimate that bats save Texasmore than $1 billion on pesticides annually.

　　经济学家估计，蝙蝠每年为德州省下了超过10亿美元的杀虫剂费用。

　　The feeding frenzy can last for hours, butas day breaks, the bats return to their roosts.

　　饕餮盛宴会持续好几个小时，不过一到破晓时分，它们就会返回栖息地。

　　If you’re up for a 5 a.m. bat shower, you should head back out.

　　要是想在清晨5点体验一次蝙蝠浴，你应该到户外去了。