Perspective is a funny thing. Because the camera is close to the bottom of the nest box, and takes pictures with a wide angle lens, a small difference in distance makes a large difference in size.
In this picture, the chick in the centre, which is standing outside the nest cup, looks much bigger than does Rosie, who is delving about at the bottom of the of the nest in the bottom left of the image.
While she is still there, the chicks starts an enormous wing flap. This shows off what great strides the chick has made in its wing development over the last few days.
Rosie is so impressed that she stops whatever she was doing in order to watch the chick.
The pins are starting to look like real feathers now.
Another shot of the chick.
Finally, it furls its wings ...
... before starting up again for a final flutter!
A few minutes later, another chick stretches its wings and you can see how much more advanced the first chick was. The pins on this chick still have little feather material.
Finally, just to remind you that although they are not quite as spectacular, Donna's chicks are still doing far better than I expected.
Donna is a very active Mum. In the first 8 minutes after we switched on this morning, she brought in food 5 times. No wonder her chicks are thriving!