Thursday 3 January 2019

Woodland bats research by Aggie Thompson

Aggie Thompson recently completed an MRes in Wildlife Conservation with Marwell Wildlife and the University of Southampton. Her research focused on woodland bats and here she shares her experiences and thoughts with us



What got you interested in Woodland bats?

My interest in bats was sparked during an internship in Southampton, where I researched the impact of artificial lighting solutions on bats in an urban Site of Special Scientific Interest (SSSI). This experience opened my eyes to many of the challenges faced by bats worldwide, driven by urban development and landscape change. Following this internship, I was keen to continue working in this field and so took a post as a seasonal independent bat surveyor for an ecological consultancy. In 2016 I continued my studies and was accepted on the MRes in Wildlife Conservation with Marwell Wildlife and the University of Southampton, which provided me with the opportunity to carry out an 8 month research project from conception to completion. I chose to develop the ideas I had formed during my internship: exploring the impact of human disturbance on bat activity and species abundance. The focus of this study was the landscape complexity within a rural area of Hampshire and how human influences such as woodland management practices and stand structure, land use, and landscape connectivity impact bat populations.

Can you describe the research you carried out during your thesis?
The focus of my research was to assess the impact of both localised woodland features and land use influences on bat populations within a multifunctional landscape. I used two different types of acoustic survey to record bat activity across a complex managed landscape in Hampshire. Firstly, I carried out transect surveys along woodland fringe habitats to assess the impact of woodland management, land use and woodland connectivity on total and species level bat activity. Secondly, I deployed static bat detectors in 21 different locations within woodland stands to evaluate if woodland structural features (understorey height, canopy cover and clutter index), along with woodland management and woodland connectivity were predictors of total and species level bat activity inside woodland.

How can the results from your thesis be interpreted and in your opinion, what are the greatest threats faced by woodland bats?
Some of the biggest threats faced by UK bats are the removal of roosts or potential roost sites, the reduction of certain habitat types required by particular species, and reduced woodland connectivity, leading to isolated woodland patches less accessible to many bat species.  The results from my research highlight the importance of a heterogeneous landscape for supporting fragile populations. Increasing woodland connectivity or the installation of buffer strips would also allow access to currently isolated foraging habitat, and selective woodland management to avoid accidental disturbance or removal of roosts is essential.

Doing this type of study in woodlands is never easy, what were the highs and lows?
The research was very hands on and was quite challenging. It required a great deal of dedication and problem-solving.  Combining both the transect surveys and static detector data collection meant lots of late night surveys followed by full days of setting up static detector equipment, not to mention all of the data analysis!

However, as someone who loves to be outside, this research allowed me to enjoy exploring different habitats in Hampshire. As well as 13 bat species, I was fortunate to spot lots of other wildlife including foxes, badgers, voles and several species of deer. One of the great things about transect surveys is that in the right habitats they are typically high reward, so every night I was seeing and recording my study animals – unusual in wildlife conservation research!





What would your advice be to anyone thinking about doing a woodland bat project as part of their university studies?

Fieldwork can be challenging, requiring technical skills for programming and setting up equipment as well as the time consuming nature of data collection, requiring specialist knowledge of bat call identification. However, bat projects typically offer a combination of rewarding fieldwork as well as interesting data analysis. These projects can also lend themselves to having a wider impact, and given that bats are found worldwide many of the findings are often relevant to populations outside of the UK. Also, given that bats are considered good indicators of habitat quality, this opens up the possibility of drawing comparisons between other species or habitats. Using this comparative approach could help us to pinpoint the real impact of human disturbance on wildlife populations.

Going forward, what do you think are the interesting areas of research in the realm of woodland bats?
It would be of great value to look into practical uses for bats as indicators, in particular as indicators of climate change or to model the impact of future management or agricultural practices. It would also be interesting to establish at what distance certain features impact bat activity, such as the impact an intensively managed piece of woodland has on the use of the surrounding landscape by bats.

We always ask this although we know it is not a fair question... do you have a favourite bat species and why?
I think the wonderful thing about bats is the variety of species. There are over 1300 species worldwide, including insectivores, frugivores, nectarivores and hematophages. They are the second most abundant order of mammals and are found almost everywhere in the world. They are a truly diverse taxa and all have their own special qualities. (Have I successfully dodged the question?!)…