Chickens losing feathers

[crazychick26201]

My 17 week buff orphingtons are losing feathers like crazy! They have been in their new coop and run about a week. These feathers are downy. I have noticed no bare spots and they are behaving normally, but do seem to be preening a lot. I am new to chickens and want to catch any problem before it gets big. Please help!

 

[ten chicks]

My 17 week buff orphingtons are losing feathers like crazy! They have been in their new coop and run about a week. These feathers are downy. I have noticed no bare spots and they are behaving normally, but do seem to be preening a lot. I am new to chickens and want to catch any problem before it gets big. Please help!

They are molting.

 

[crazychick26201]

How can I tell this for sure? Also their their tail feathers have black splotches on them before they fall out.