Two Of The One Thousand Five Hundred ...

... feathers with which my pair of long-tailed tits will line their nest. 

They probably started on the nest weeks ago making a framework using moss and hair bound together with cobwebs. They will have then covered the outside using lichen. They're working hard on the feathery lining. When it is finished the barrel-shaped nest will be have a small hole at the top and be stretchy to accommodate their brood as the young birds grow.