You never mentioned whether he eat a small pieces of the pit or whole.
Check his poop to see if he passes the pits whole. If he does, he will be OK, if he doesn't, watch him carefully for any symptoms and give him A LOT of a mild corn silk tea (pour one cup of water that just finished boiling but is no longer bubbling over 1tsp of dried corn silk or half the fresh silk of an ear of corn), mix this in equal parts with Aloe Vera Detox and add 1 tsp of sugar (glucose is believed to bind cyanide or, at least, that is the reason they gave for Rasputin surviving cyanide poisoning -it was put in a very sweet wine).
The thing about cherry pits is that the toxin is inside and the shell is real hard to crack so, usually, when people or dogs eat cherry pits, there isn't really much danger to them because they usually swallow and pass the pit whole which prevents the poison from been absorbed by the system. But it's different with birds, because they can crack the pit so, if he did crack them open and ate the inside, he could be in trouble.
If it were my bird, I would definitely take him to the vet immediately.
