There has been some conflicting info posted in another thread. I am hoping to clarify it here.
Please Note: no one here is a vet, this is information I was told by my vet and have researched. PLEASE DISCUSS THIS WITH YOUR VET FOR FURTHER CLASSIFICATION.
It is my understanding that Human Mouths have bacteria that although it may be a Positive Bacteria for Us, It is a Negative Bacteria for our birds. Birds that are allowed to eat off our forks, out of our glasses, take food from our mouths, or kissed by our mouths on their beaks are highly susceptible to Bad Bacteria for them resulting in sickness and even death. It is NEVER a good idea for any reason, including the risk of a bite to kiss our birds on their beaks.
Please read this link:
http://www.cockatiels.org/ownersandenthusiasts/avian-bacterial-disease.htm
In my house, I kiss my birds lightly on the top of their heads if they are in the right mood and I see by all indications from their body language that it is okay. They will allow my Hand to lightly bend their head down for a kiss on top. I always keep my hand lightly guiding their head so I can't be caught off guard for a sucker punch. Another thing I do for kisses is ask for a kiss if again they are on the right frame of mind for it and I pretend to kiss their beak with my finger and make a kissing sound. This works for my flock and is safe for all of us.
I expect Dave our Health Room moderator to chime in here and set us straight with more facts. So keep reading and watching........to be continued....................