On my Droid 4 Calendar I can choose "Calendars to display" and choose 'Contacts Birthdays and events" though that may be from enabling it on Google Calendar from the PC/Web connection initially.
I keep all my contacts sync'ed with Google so Contacts, Calendars, etc...all point to my google user account only, and I have nothing set to show/use the "phones" calendar or contacts.
Yep...looks like one of the default calendars I added via the PC/web on google.com Calendars. It reads it in from my Google sync'd contacts and created it....and I can select it to be displayed in my Calendar on the phone.