I don't have the disk to hand, but if there's nothing there you can get loads of stuff off the web. If you can be specific about what bird calls you want you'll find a lot of academic sites have examples you can download. Failing that, you could always try recording your own.
This is a site I've used numerous times to find all sorts of sound effects. I entered 'birds' in the search and it returned 200 different bird sounds. Hope you find this useful.
Thanks for all the reponses. I checked out the suggested sites and found great sound clips. However, how do I save these so that I can add them to a VMS audio track?
If you're using Firefox you're given the option of saving or playing the clip, in IE you need to right click on the link and then take the option of saving it.