Guiness strikes..again

when my female cockatiel Sweetie is sitting on her eggs, like she's been doing for the past few months!, my male cockatiel Birdie gets very hyper,excited,and protective. he can't seem to stay away from her cage and is always hanging all over it.
well, her cage happens to be close to our quaker parrot's cage, Guiness. yesterday i had left the room for just a second and next thing i heard was some massive screaming. i rushed out and found Birdie on the ground with a feather pulled out and a bleeding toe. great.
he had somehow jumped onto Guiness' cage and like he is prone to do, Guiness bit Birdie's toe through the bars.
so off we went to the vet. for a bleeding toe. again. (this happened several months ago too because Guiness bit Sweeties toe...she has no toenail anymore on one toe, and a very mishaped nail on the other foot. see description of incident here http://lani-lifesjourneys.blogspot.com/2007/03/poor-sweetie.html)
the vet thinks Birdie may fare better than Sweetie as far as keeping his nail, but only time will tell. in the meantime he gave him an antibiotic shot and some stuff we need to give him at home to prevent infection.
i love our vet, he's really good. and the staff know us too well from our many visits over the years. its sad when you become a regular at the vets office. sigh.