Willow tits are a special bird in the tit family, as they are unusual in their nesting techniques. They excavate their own holes in standing deadwood, a rare habitat, making suitable nesting sites scarce. They will not use traditional nest boxes like many other species, meaning a little bit more work must be put into helping them out! Join me on a trip to Pollybell farm, where I take you through the steps we are taking to give these endangered little birds a helping hand…

We drove through Pollybell, a family-owned organic farm, which Nottinghamshire Wildlife Trust has worked closely with for approximately 20 years. There are two Sites of Special Scientific Interest (SSSI) on-site, and the farm is home to over 185 species of bird with many being endangered or at risk. I was pleasantly surprised by the vast range of wildlife I saw in such a short space of time! In the 5-minute drive through the farm, we spotted a sparrowhawk sitting on a telephone wire, a group of roe deer on the edge of a woodland, a kingfisher in the ditches, and a hare hopping along a field. The air was fresh and full of bees.

We walked over to an area which had been previously identified by Mark Speck, NWT's Senior Nature Recovery Officer (North), as being a suitable habitat for willow tit. The species had been recorded there a few years ago, but the population has declined in line with the national trend. Lisa Channing, NWT's Farming & Wildlife Project Officer, explained that these birds are quite picky in their habitat, they occupy damp scrubby woodland and post-industrial regeneration scrub. They also like to be close to water, as this increases the likelihood of rotting wood (which they nest in), as well as the abundance of invertebrates – which means more food!

Next, we had to identify the correct trees to place our nest boxes on. There is a lot to consider when putting up a nestbox for a specialised species like willow tit, including the direction it is facing, the species of tree it is placed on, the height it is placed at and where the tree is. As the name suggests, willow tits excavate their own nest holes in standing, decaying willow and birch, and use the resulting woodchippings as the base of their nest. We wanted to avoid the boxes facing south-west, where our wet and windy weather comes from, as well as making sure they wouldn’t be in direct sunlight for too long throughout the day – making it too hot for the tits young to survive.

The nest boxes were placed approximately two metres up the tree from the ground – as willow tits prefer to nest at lower heights, but not too low that they are in danger of being predated by ground dwelling animals like foxes or badgers. They also like to be close to water and in dense scrub, so these trees below seemed appropriate (although a bit spikier to get to for us!).

Once we had identified the suitable trees, Lisa and Bryony Harrison, Biodiversity Project Manager at Severn Trent – long term partners and funder of this project - started putting them in place. Matthew Guest at Pollybell was also a huge help, getting into some of the more tricky areas for us!

As well as specifics when putting up nestboxes, there also had to be careful considerations when they were made. As mentioned earlier, willow tits won’t use general bird boxes, so we got creative and had ours handmade by local nestbox maker, Jim Lennon. To ensure the willow tits could excavate their own holes, we filled the boxes with rotting wood – imitating their ideal nest site – and then cladded the outside of the box with silver birch bark. The willow tits can identify this wood and excavate their own hole into the box, like they would in a rotting tree, so they should be quite happy with this replacement if they are struggling to find suitable habitat elsewhere.

We put up 5 boxes in total, some cladded in birch and some not, as research has shown that although ideally, they would prefer a box that looks like a tree, they have been found to nest in boxes that aren’t cladded too – so we are testing to see if they have a strong preference by using both!

Willow tits have one brood, the clutch being laid between mid April and mid May. We won’t risk disturbing them by checking the boxes until much later in the year when it is safe to do so. When we do, we will be able to tell if the box has been successfully used by willow tits if a hole has been excavated in the rotting wood. It is very unlikely that any other species with similar nesting techniques would use a box at this height, or in this particular area. Willow tits won’t use the same nest hole twice, they will excavate a new one. However, they have been found to excavate new holes in the same tree. So, we made the bottom of the nestboxes removable, so that we can re-stuff the nestbox with rotting wood ready for willow tits to excavate a new hole the following year.

In total, we are putting up 20 willow tit boxes across the county, with the greatly appreciated support of a number of farmers. This is all part of our wider vision to work with farmers and landowners to connect habitats and form a nature recovery network. This is a huge part of what we do to restore habitats across the county and allow wildlife to thrive in these areas. We simply would not be able to achieve our 30 by 30 vision without this essential collaboration with farmers and landowners.