bird的复数形式怎么写

例句：

1、This species of bird is decreasing in numbers every year.

这种鸟的数量在逐年减少。

2、 The area has a wealth of bird life.

这个地区栖息着大量的`鸟。

3、The lake is noted as a home to many birds.

这个湖作为许多鸟类的栖息地而闻名。

4、Huge numbers of birds had flocked together by the lake.

成群的鸟聚集在湖边。

5、 The male and female birds take turns in sitting on the eggs.

雄鸟和雌鸟轮流伏窝。