Our annual nest box monitoring programme is nearly over for this year. We do a weekly check of 24 boxes. We monitor three different types of woodland with eight boxes in each section. The aim is to find out what effect our woodland management has on the number of birds using nest boxes. In theory as the woodland matures, the reliance on nest boxes should decrease as more natural nest sites become available.

On Sunday I carried out one of our weekly checks and all we had left was one family of blue tits and one family of wrens. Our boxes have small holes in and are primarily designed for blue tits and great tits which is what we usually get. Wrens generally use open fronted boxes but ours have ignored that rule. Last year we had a box that one week was empty and the next was completely full of moss. We never did find out what had built it but we had our suspicions. It was never used in the end but this year they came back and used a nearby box. I checked it at the weekend and was so happy to be able to see through a tiny gap in the moss. As you can see from the photo, I saw two very healthy looking chicks and three as yet, unhatched eggs.

Wrens also use nest boxes for winter roosting and up to 60 have been recorded in one box! During the breeding season the male constructs several globe shaped nests from leaves, grass and moss and then the female decides which one she wants to use. Once she has chosen a suitable nest site, she will line it with feathers. Wrens usually lay 5-6 eggs and the young are fed by both parents. It only takes 15-20 days before the chicks are ready to fledge the nest.

Laura Preston, Falls of Clyde Ranger
Help support our vital work and join us today!