conditioning

I agree with what Bezz said. A good feeding routine is the key to successful trapping of your birds. Overfeeding your birds causes them to not trap when you call them in and it's also the reason why some birds won't fly, route or trip. Give about 1-2 tbs. of feed per bird for the morning feeding and the afternoon feeding. Never leave food out overnight. The only thing that should remain available to them 24/7 is fresh water and grit. Use a feeding call everytime you feed so that they get familiar with it and they will know when it's time to eat. Leave the food in the loft for no longer than 10 minutes. This is enough time for each bird to get their fill. The birds that trap when called will eat and the ones who don't will not. They'll have to go hungy until the next feeding. It's hard but you have to be strict! You can be sure that when they hear the feeding call for the next feeding the ones who didn't trap when called in before will be the first ones to trap this time around.

Henry

They are overfed so they are not responding to your call. Feed less. Young birds (less than one year) can fly 1-2 hours if healthy and not fat. Older birds end up lazy, but if they fly they don't for long. They rather mate than fly. Who can blame them? LOL!

Depending on the weather and how your birds perform you should adjust your feed. I start with 1 ounce (2 tablespoon) per bird. Vary less or more depending on their performance. For example, I was feeding mine that amount and they ended up fat and obviously rather not fly. I ended up giving them 3/4 ounce and they started flying again. Now if you underfeed them they will not fly as well. They rather go down right away and enter the loft looking for food. So there is balance--not too much, not too less. That ended up as an art. And the weather plays havoc, too. Some of my birds love to fly during bad weather--windy, cold, etc. Most rather prefer good weather.

To condition them is to fly them almost everyday. When you do that they will end up looking muscular and their endurance improves. Obviously they become less looking fat. You can also road toss them after they started ranging/tripping (going far away from your place).