How to add Facebook Birthdays to Calender in OS X

I have recently purchased a Mac Mini running OSX 10.8.2 (upgraded recently) I linked my facebook account to OSX ML. I have my FB contacts imported to Contacts but, the is no Facebook Calender in Calender app. It is available in iOS on my iPhone & iPad, but not on my Mac Mini?

Since the Calender app is a Mac app, not a 3rd party, and I was able to sync my data over iCloud and iTunes Match, why isn't there a FB Calender in OSX ML like iOS?