Fifty minutes later the female comes in with the first piece of moss. The great tit pair have decided that they like it here and unless there is a change of plan, have decided to build their nest here.
What is not generally realised is that both bluetits and great tits are normally single brooded. If their first go at nesting fails, that's it for this season. The reason for this is that the main food for the chicks is the little green caterpillar that is to be found on oak trees at this time of year. This crop of caterpillars is only available for a short period in May/June and so a second brood of chicks would miss it.