Joanna has been back to Kielder today and has sent in the following report:
I saw some interesting activity around nest 1 between about 12:45 and 13:15. I was looking through my scope from the south shore and could see a pair of buzzards hunting over the fell below Monkside summit. The incubating osprey’s head was bobbing around, and I thought the male would have seen them off had he been near, but he was nowhere in sight. The buzzards moved further east, but about 20 minutes later one was right over the nest. An osprey came at it, and there were some acrobatics before the buzzard went off. I thought I saw another osprey to the west as the buzzard flew east, but couldn’t be sure. The chasing osprey went back to the nest and took up pole position (i.e. he perched on top of the camera pole!) and everything settled down.
I then went to the Castle, where the staff had been watching just before the scrap; apparently an osprey landed and the incubator flew off. So it seems likely to me that the male was incubating initially and the female was either eating or fishing, so he was stuck until she got back, then he was off to defend his patch.

Nest building from the Video (c)Joanna Dailey
Also of some interest (to this osprey anorak!), on nest 2 the female was off the nest and the male was incubating when the staff turned onto that channel. Whilst I was watching, the female flew in and they swapped. Over the next 10 minutes the male flew in with some large twigs and started building up the nest on the opposite side to the camera position. It looked more substantial than last week even before that, so the cold winds must be getting to them!