The babies are now 23, 21 and 19 days. They are loosing weight.

Chick #1 4/14 (l9d) weighed 116g, today at 23d weighed 105g; chick #2 4/14 (17d) wieghed 106g, today at 21d weighed 105g; chick #3 4/14 (15d) weighed 93g was gaining but today at 19d weighed 97g.

Is this normal? I don't think their crops are as full ad I am not sure that Bitsy and Roscoe are feeding them as often. Do I need to step in? When I had them out this morning they all seemed to look good. This afternoon-evening chick #1 seems a little weak, although it could be my imagination.

Totally normal. They're getting close to fledging age, and they couldn't fly properly with a huge heavy crop weighing them down. They're also not growing as fast as they were before, and don't need as many calories.

You can always feel their keel bones to check the appropriateness of their weight. It's not an easy thing for an inexperienced person to judge, but you should be able to feel the bone sticking out somewhat but not excessively. You can also check them at night to make sure they're going to bed with a reasonably full crop - not overstuffed like they were a week ago but not completely empty either.