In January 2010, Friends of Adel Woods, under the expert tutelage of Steve Joul, senior countryside ranger with Leeds City Council, put up nest boxes and seven bat boxes in Adel Woods.
The bat boxes were fixed to two trees about 25 yards to the right of Crag Lane, just before reaching the Rugby Club car park. Four were placed around the trunk of one tree and three around the trunk of another nearby. The bat boxes are placed together around the trunk so that the bats have a choice as to which one they prefer.
Bat boxes differ from tit boxes in that, rather than having an entrance hole in the front, they have a slit in the base through which bats can climb up into the box. In the picture above, Steve Joul is holding a bat box and you can see the slit just above the number 25.
The function of a bat box is also different from the function of a tit box. Whereas tit boxes are used for nesting by a single pair of tits, sparrows or nuthatches, many bats will share a single box for roosting and bringing up their young.
The fallen bat box 
Number 23: not ET!
Note the slits across the back plate to help the bats to climb up inside.
It is illegal for people without a bat licence to interfere with bat boxes once they have been put up, and so our bat boxes have been untouched by human hand for the last nine years. This weekend, Rob, one of our committee members, found that the back plate of one of the boxes had rotted and the box had fallen to the ground. So this was a great opportunity to find out if the box had been used.
On opening the box, we found no evidence of bat use, but the box was full of cobwebs and bird nesting material (bats don’t make a nest)!
The inside of the bat box 
The contents separated out
The bottom part of the nesting material seemed to be small bits of straw, while the upper part seemed to be moss and manmade fibres which we often find in tit nests.
What species of bird or birds could have built a nest in the bat box? The obvious candidate is the tree creeper which usually builds its nest behind the loose bark of a tree. The website of garden-birds.co.uk says that the treecreeper nest is made from twigs, grass and moss lined with feathers – which seems a reasonable description of the materials found in our bat box. However, there seemed to be a clear distinction between the lower and upper part of the nesting material, which raises the intriguing possibility that treecreepers originally nested in the box, but that later a pair of blue tits or great tits used it to build a nest above the treecreeper nest. We’ll never know.
Treecreepers are a common sight in Adel Woods – we had some excellent sightings on our birdsong walk in May – have a look at our blog entry
Friends of Adel Woods have organised a number of well attended and well received bat walks over the years – here is the report of our walk on 4 September 2015
Friends of Adel Woods 