gouldian fledgling with line up his head

[ac12]

This is something that I have never seen before.
I have a YB fledgling with a line up the center of his head.

Yesterday there was a spot at the top of his beak. I thought it was his nostrel that was not covered by feathers.
I did not notice it before and don't see it on any other bird.

Today that spot looks like a blood scab, a bump and not a hole.
And from that spot to the top of his head is a STRAIGHT line of skin, no feathers. This line was not there yesterday.

The other fledgling looks normal, w/o this line on his head.

They are both being foster raised by a pair of society hens.

Any idea of what is going on?

[finchandlovebird]

Gary .... you know we're going to ask for a picture ;)

[Ginene]

Dolly's right...

[ac12]

I knew that.
But this is an active fledgling, so its hard to get a pix of him.
I might have to catch him to get a pix.

[debbie276]

Could he be being plucked by the society's? Maybe hitting his beak and rubbing his head on something over and over like a food dish?
Pictures would help