How to find a calendar delegate owner?

I recently took over someones IT position with no overlap for learning details of thier system. Basically Im trying to find the owner of a delegated calendar mailbox. I opened calendar on the previous IT persons computer and there are several delegated mailboxes. But I have no way of finding who shared these and who controls the original mailbox. Is there a way to find the owner of a delegated mailbox?

If it helps, we run our own email and ical service with OSX server 10.6.

Thanks!