Last fall when I took the tiels to the vet to have their nails trimmed, Riley weighed in at 90 G and Bailey recently weighed in at 94 G.

When they went in to have their nails trimmed recently, Riley gained 2 grams and Bailey went down 6 grams. (A 4 gram difference between them.)

I asked the vet if he felt their weight was good and he said their weight was where it should be, which made me really happy because I know they're eating well or as well as they can eat with me.

I'm curious what do your tiels weigh in at?

My Keith is 84g, Mr Darcy 79g and Bubu is a massive 99g, at the moment.

There's a lot of individual size variation with cockatiels, and a weight that's just right for one bird might be too much or too little for another. The best way to check is by feeling the area around the breastbone, and your vet probably did this. My flock varies from 75 to 100 grams, and their weight tends to go up or down depending on the season.

I didn't know that in regards to weight and season.

Neither did I, until it happened enough times in my flock for me to realize that it was a recurring pattern. They put on more weight in the spring and summer. This is usually the best time for breeding, and I think they're building up their physical resources for this, whether they're actually going to breed or not.