At one point the four adults are drawn to a window by bird calls.

He usually has a catchphrase which is similar to a bird call.

Living in the country, I'd learned to recognize bird calls.

General Kuo first became aware of the attack through the bird call.

It is the lowest known bird call, like a "boom", which people can only just hear.

She likes bird calls, and can do them better than the President.

They bought him tracks of bird calls, which he learned.

They did not change pitch as bird calls do on planets which have been converted to human use.

For its weight, this species has one of the loudest bird calls.

After a long time, she heard a tiny sound, a soft whistle like a bird call.