I know this is way late but, HAPPY B-DAY BRAD! 
Thank you for bringing depth of character and story “back into fashion” at the cinema. Good luck with your future movies, as well. You truly have found your home at Pixar.
PS That looks very yummy, CL. (And the cake does, too). 
But Happy Birthday, Mr. Bird. Thank you for the masterpiece that is Ratatouille!
I wonder what Mr. Bird did on his belated birthday. Any guesses?
Brad probably had a party at the studio and then went home early to spend the rest of the day with his family, but for all I know he did something far more extravagant.
~~=oP
I would like to think he went out to a very fancy dinner with his wife, then maybe another day, familiy time, then a huge party with the people at Pixar in that oder.
What everyone else said. It would be pretty sfe to say that he did celebrate it with his family. He is a family man after all.
I also agree with a majority of the public in that the dude probably did celebrate with his family and friends. They probably watched Family Dog together… (snigger)
– Mitch
Or maybe The Incredibles.
I saw that comment a 100 miles away. 
I honestly don’t believe Brad Bird watched The Incredibles on his 50th Bday, because a birthday of that magnitude should be a day for celebrating yourself. Why watch an animated film based on your own family when you can spend your special day together in real life?
~~=oP
The Star Swordsman - Haha! Yeah, that would seem plausible, but I have to agree with PV on this in that he probably didn’t watch one of his own productions (even though I did mention Family Dog).
Actually, I always thought it kind of weird to watch a film that you made on your own birthday. It’s like screaming to the world how vain you can be and how fantastic you are, in my opinion. But that’s just me…
But yeah, PV has a point. I’m sure the Bird would rather spend time with his family.
– Mitch
It was just a funny, yet predictable suggestion from me, what else are you to expect huh? 