This week is National Nestbox Week which encourages people to put up nest boxes in their gardens. This is a great idea and focuses attention on providing these features as the birds first start to pair up and scope out nest sites. We have birds nesting in various locations around the garden but, for some reason, I had never got around to adding some more purpose built nesting habitats for them – something I have now rectified!
But why stop at providing habitat for garden birds? Don’t forget that gardens are vital to some of our most common bat species, such as the common pipistrelle and the brown long-eared. Attract bats to your garden and you will be able to watch fantastic aerial displays as the sun goes down throughout the summer. There are lots of tips from the BCT on how to attract bats to your garden.
There are many designs of bat box on the market and plenty of designs which you can make for yourself. I realised that the offcuts of wood we had in the shed provided everything I needed to make a Kent Bat Box – one of the simplest designs and one I would strongly recommend to anybody putting one together for the first time. This box is very simple and creates cavities which small bats such as common pipistrelle can use as a roost. This video shows the kind of tight niches which are used by pipistrelle bats.
Bats fly in the garden regularly throughout the summer and one of them – probably a brown long-eared – uses the porch as a feeding perch. I know this from the little piles of moth wings which suddenly appear some mornings, often 5-10 of them. The bats bite off the wings of the moths they have captured, eating only the nutritious bodies of the moths and leaving the wings to flutter down. Just opposite the porch is a holly tree and this struck me as the ideal place to put a box, seeing as I know the bats use this little niche of the house and garden.
I also put up another box on the tree beside it, facing the opposite direction. We were recently called out to climb a tree to check a bat box where the tree was to be removed. The bat box had only been up for a few months and was clearly un-used so we were able to inspect it and take it down without causing disturbance to any bats. There was nowhere else on the site to place the box so I have put it up in the garden instead – I am interested to see if either of the boxes are used and whether a particular design might be preferred.
If you are putting up a bat box, make sure it is high above the ground (at least 4m if possible) to deter predators and ensure that there is not too much disturbance to the bats as you use the garden. Another important point is to ensure that there is a good fly-in and fly-out route for the bats. This can be achieved by imagining the bats dropping from the entrance in an arc which is 1-2m out and 2-3m down. If you have left this space for them, they should be able to enter and exit the box. Another important point is to allow them to emerge into some cover, if possible, or out along a hedge or tree line. Bats use these vegetative features for commuting around the landscape and placing your box in such a location should increase the chances of a bat moving in.
The designs for the Kent Bat Box can be found here and all you need is a plank of wood, some smaller wood for battons, a saw and a drill (or hammer and nails). The design is very simple to follow but below shows the step-by-step progress of the construction.