Shane Stigant, MBG member, explains his interest in bats and experiments with different styles of bat boxes
I have always been a keen observer of wildlife but my interest in bats came after a realisation that I knew relatively little about them. Like most people, I had fleeting glimpses of them at dusk or as a child I remembered hearing them too. To my older ears bats are now silent, so I bought a bat detector and joined the Manx Bat Group to learn more. When I found out more about where bats feed at night and roost by day I realised that I could bring the bats to me, to get a closer look. I had bird boxes in the garden so why not build somewhere for bats too.
I started by adding a second layer of cedar cladding to an extension I built on the east facing side of my house. By leaving a gap between the layers it provided a space for bats to squeeze into. After a couple of months I had my first visitor, a Common pipistrelle. I knew one had arrived because it was leaving calling cards on my windowsill. That’s no problem as bat droppings are high in nitrogen and a welcome addition to my garden. A garden that is full of midges in summer and Pipistrelles eat a lot of midges so bats are very welcome.
My second bat space was provided by my children who made a bat box at a Manx Bat Group bat box building session. That one was put on the South facing side of a dormer and had a regular occupant after about a year. Another space was provided by a layer of cedar cladding to that dormer at the West facing side of the house. This space remained unused for several years and I thought it was probably too cold, being out of the sun for most of the day.
My aim was to create a maternity roost with an infra red camera inside so I could observe the bats day or night and really start to learn about them. Through the Manx Bat Group I now, importantly, gained a licence from DEFA to inspect bat boxes that enabled me to survey boxes for the MBG including my own boxes that did not have a camera.
My attempt to provide a maternity roost was a triangular shaped box to go on the South facing gable end of the house. It was large enough for several bats, had perches for the bats to hang from and an infra red bird box camera focused on the perches. I learnt that bats move from roost to roost and can’t be relied on to stay in one place. I waited a couple of years, but they never chose to move in.
My little pip moved from the cedar cladding and didn’t come back for about six months. While it was away I installed a couple more cameras behind the cedar boards in the voids made by the baton spacers. At this point I learned that small birds also seek out crevices to roost in. Only this time the calling cards were much bigger and the competition was probably preventing the bats from returning. I had hoped that the two could literally hot bed together with birds moving in at dusk as bats moved out for the night. This sadly could never happen as birds will even peck bats to death during the winter hibernation. I ended up with a compromise, reducing the entry aperture to suit bats in some voids whilst leaving others for the birds. Bats seldom visit this space now and I had not yet caught one on camera but small birds such as Blue Tits and Sparrows are more frequent in the camera less spaces where they have not been excluded.
The box I had planned as a maternity roost got taken down after a couple of years of neglect and the camera was used in another experimental box. This time I made a smaller wedge shaped box. The Infra Red camera occupying the wider, top end, and the narrow, bottom end has a 17 mm gap with a vertical crawling board for landing and access. I paced it right next to the popular box that my children had made in the hope that it was all about the location and I waited and watched from the comfort of my study.
After about a year with no interest and still not getting a bat in a box with a camera I decided to alter this new box in some way, to make it more appealing. Jim Mulholland, a bat expert from England visiting the MBG suggested painting the inside of the box black as bats like to be completely in the dark. That didn’t work either. I was beginning to wonder if the bats just didn’t like the cameras and were avoiding them. Then Nick Pinder, our Chairman and Recorder, recommended an article by Anthony Atkinson, a member of the Cornwall Bat Group who was experimenting with large boxes like bee hives suspended in trees. His boxes had frames lined with insulation material that were proving to be very well used. I started using old plastic containers as these would be weather proof and I lined them with styrofoam. That did not work for bats but some birds did investigate them.
During a heatwave in 2021 the bat using the cladding on the East facing dormer moved out. However, a bat, and I presume it was the same one, started leaving calling cards, for the first time after about five years, on the windowsill under the cladding of the west facing dormer. This space is much cooler as it only gets the sun in the afternoon and evening. I presume this space, though not immediately desirable to a bat and very rarely used, is now a safe haven and may be a vital retreat, when things get too hot.
For my next experiment I scaled up with an old 25 L plastic drum and sank a wooden frame into it. The frame has seven thin wooden dividers that are lined with cork mat. The wooden frame is fixed into the drum with insulating expanding foam. I hoisted this up into a sycamore tree in my garden where bats would have plenty of space to swoop in and out. The wedge shaped box was also lined with cork as a further modification.
Soon the 25L drum started to get up to three bats using it and, at long last, I had a Common Pipistrelle take up residence in the wedge shape box with the I.R. bird box camera.
It took up residence on 11th November 2021 and after a day it stopped moving completely and appeared to go into hibernation. I was hoping to watch some sort of behavioural characteristics but to be honest the live view was like watching a still photograph, with just the slightest of breathing movements every couple of minutes. Occasionally I would find that it had shifted position slightly so I may have missed it stretch or yawn. It might have even ventured out to stretch its wings and grab an opportunity to feed but if I wasn’t looking I missed it.
On 18th of January the bat left its roost with the camera. It is now February and I had hoped it would stay through the winter but the bat thought otherwise. I hoped it had moved to the box next door but that one is empty too. I’m confident it will be back again some time and I’ll get another close look via an Infra Red camera. For now I’m happy to have provided plenty of potential safe roost boxes in my garden and if it chooses to come back to the camera then I’ll be delighted.