Moss already...surely not

Er, yes we do have a small covering of moss at the bottom of our nestbox. The first thing I thought was that it couldn't possibly be moss. We do live in the south but its not even March yet. From the nestbox diaries I have seen, they don't start bringing in nesting material until mid-march to early April. This certainly has worried me, and I am not sure whether the parents will have a chance of bringing up a successful brood. Surely there won't be enough insects to feed the chicks. We'll have to see what happens next.

For some reason, taking still images with the nestbox camera doesn't work particularly well, and the quality of the image below isn't that great. You should still be able to make out the darker plant material on top of the wood shavings. This really surprised me!