One tree swallow was in the nest and the other on guard outside. 一只树燕子在窝里，另一只在外面站岗。

A fierce but one-sided battle took place, 一场激烈但一边倒的战斗发生了，

and the nest and eggs might have been thrown to the ground, had not Duncan protected his tenants by driving the sparrows away. 如果邓肯没有赶走麻雀来保护燕子的话，这些鸟窝和鸟蛋可能会被扔到地上。

In about two weeks the eggs were hatched, 大约两个星期后，这些蛋就孵出来了，

and the parents were on the wing from daylight until dusk, scooping up in their wide mouths many hundreds of flies to feed their babies. 燕子父母从早到晚都在飞翔，用大嘴把数百只苍蝇抓来喂它们的孩子。

In about two weeks the young swallows, dressed very much like their parents, came out on the roof to be fed. 大约过了两个星期，小燕子们越来越像它们的父母，飞到屋顶上来吃东西。

A few days later they left their little home forever, and were soon hunting insects over the fields and through the barnyard. 几天后，他们永远地离开了小家，很快就开始在田野和谷仓的院子里捕捉昆虫。

But the bird house was not long unoccupied. 但是鸟屋没多久就没人住了。

The bluebirds had reared their first brood, 蓝鸟们已经养育了它们的第一批幼鸟，

and about a week after the swallows had left, Duncan saw new tenants inspecting the little dwelling. 在燕子们离开大约一周后，邓肯看到新房客们正在检查这个小房子。

A few busy days of nest building, and then the male, in sky-blue coat and reddish vest, perched on the roof, singing softly to his hidden mate, who sat on four blue eggs in a simple nest of hay. 过了几天忙着筑窝的日子，然后这只雄性，穿着天蓝色的外套和红色的背心，栖息在屋顶上，轻声地向他隐藏的伴侣歌唱。

Still busier times followed when the eggs were hatched, 蛋孵出来以后，日子就更加繁忙了。

and every day the parents made scores of trips to the fields near by for caterpillars and other insects to feed four gaping mouths. 父母们每天都要到附近的田野里跑上几十趟，寻找毛毛虫和其他昆虫来喂养四张张大的嘴巴。