How to Play
Some insights on the Birdman mod program from contributor Kay:
The mod Birdman is basically a cheat and editor. Like if the bird is sick you can use it to max out the birds health, or health of the cage or egg.
I think it is a way around the limitations because they used to want lots of young and then trade them back and forth. the program was expensive I bought two of the cds, still have them, but it's all in Japanese, they got all the birds together and got some English in there, I think that's the copy you have. I think each type of bird back then with the program was almost 90.00 at the time and then paying for the shipping from Japan.
You can find instructions for the Birdman program on the archive of Don's Attic.
English 
Japanese 
Comments and reviews
dude, i searched EVERYWHERE on the internet for this game a few years ago and couldn't find any trace of it, I'm so happy to see it on here. I remember the only way it was available used to be to buy a super expensive used copy off ebay that would have to ship from japan. such a cool little piece of virtual pet history.
No comment nor review for this game at the moment.