Well, birds always pretend nothing is amiss, it's self preservation. That's why you hear people say they looked fine right up to when they died - my Neil did (looked and acted normal, I mean).

The only sign anything was wrong with Jesse was he was sitting on the bottom of his cage, and if you talked to him, he would not answer. That was when he was 1 yr old. He's 11 now. TG we knew something was up. I sat with him all night with a heating pad and an eye dropper, to feed him, keep him hydrated.

Got him to the vet in the am - she ran tests, got him on anti biotics right away. He had some sort of infection, as little birds will get. He recovered in a few days and has been fine since.

Birds are born full of bacteria, and generally their mother's feedings help them build immunities to those diseases, so they fight them off and survive. Pet store pets (like Jess) have a high mortality rate at 6 mos to a year because thay are eithe hand raised or taken too soon from the parents - so my bird friends tell me, anyway.

Same is true with some reptiles.