Last year I entered in the Royal Adelaide Show a double page of this topic. Here is a photo of this spread. I made a little book - Bird guide - to reproduce what a person would write and draw when studying birds. Also did a collage of two birds.
I remember my teacher in grade 7 had a brother who was a professor in Ornithology. He studied different bird calls and recorded them on tape. He later received a grant to produce a machine, which was placed in the adelaide parklands. This machine had all his recordings of different species of birds in surrounding Adelaide.
You pushed a button on this machine and it would play about 12 different bird sounds. This was fascinating as a child. Unfortunately this machine is no longer there, but the time and effort to record, follow in detail and observe birds, was interesting and rewarding for this man.