As you purchase Birdview, you obtain a login name (Administrator, by default) and password. Upon entering these, you are logged in as Administrator, i.e. user with a complete set of permissions. It is quite logical indeed, as it is you who are supposed to grant other users their respective rights and permissions as users of the system.
Administrator is a global access level. To give a simple analogy, the Administrator relates to the whole system as a Project Owner relates to his or her project.
Consequently, Administrator has no defined permissions as a member of a project. That means that, as such, Administrator access level has no place among project access levels.
However, Administrator may have any permission he needs in relation to any project, as a non-member. View it as supervisory rights, Administrator being the ultimate supervisor inside the system.