Continued agricultural expansion and human urbanisation aren't good for bats. They are losing the habitats that they need. It would be hard to put a stop to a lot of the habitat loss that goes on. We can’t prevent houses from being built in urban areas, for example. We therefore need to find ways to mitigate the effects of these processes.
Ecologists have developed a standardised tool capable of distinguishing between the calls of different European bat species. It is hoped that iBatsID – a free-to-download piece of software – will provide a much-needed shot in the arm for European bat conservation.
European bat populations have declined significantly over the last 50 years, and the conservation community has lacked a standardised tool capable of more accurately logging bat numbers and species prevalence across the continent. An international team of ecologists used 1,350 calls of 34 different European bat species from EchoBank – a global echolocation library of more than 200,000 bat calls – to create iBatsID.
It is hoped that iBatsID will make the job of European bat conservationists that little bit easier, and help to create a more accurate picture of continental bat populations. I spoke to Charlotte Walters, PhD student and lead author of the study from the Zoological Society of London (ZSL), to find out more about the ambitions behind this new tool.
"My supervisor, Professor Kate Jones, runs a project called iBats
, which uses citizen scientists to collect bat calls," began Walters. "These individuals follow set routes and they repeat these routes every year. This provides an idea of how bat activity is changing over time. The main drawback with the project, however, was that we didn’t have a consistent way to identify the bat calls. Our idea, therefore, was to develop a tool to identify bats in the same way all over Europe.
I asked Walters about the ways in which the lack of a standardised identification tool has hampered bat conservation efforts in Europe.
"Two people might be monitoring bat populations in Bulgaria and the United Kingdom," she explained. "If their identification methods differ slightly, their results can’t really be compared. You might think that a species is doing really well in the UK but really poorly in Bulgaria. However, the identifications that have been collected might not actually be of the same species.
"We wanted to develop an identification system that can be used by anybody. iBatsID eliminates the possibility of a single person misidentifying bats in a particular country. We wanted to develop a tool that was consistent and that could be used everywhere, in exactly the same manner. Results produced by our system are completely comparable. Previously, a lack of comparable results has prevented us from being able to see how bats are doing across
The new tool, details of which will be published today in the British Ecological Society’s Journal of Applied Ecology
, is able to correctly identify most European bat species 80 per cent or more of the time. However, the calls of some species are more difficult for the system to distinguish. In terms of the species Myotis
, for example, the software only enjoys a 49 to 81 per cent success rate. I asked Walters whether she and her colleagues had any plans to improve their system’s effectiveness in this respect.
"We are currently investigating different identification methods," she replied. "At present, bat calls are identified by reviewing spectrograms that we make of the recordings. This is a 2D representation of what the call looks like. However, some UCL students are now looking to develop an entirely new method of reviewing bat calls.
"Sound is actually three dimensional so instead of taking these one dimensional measures, the students are treating the sound as a 3D shape. They are using this technique in an attempt to obtain a better identification of Myotis
calls. This project is still in its infancy. Whilst it has delivered some promising results, it is still too soon to say whether or not it will be able to more accurately classify Myotis
The EU Habitats Directive – legislation brought in to tackle the problem of falling wildlife numbers – now offers protection for all European bats. I asked Walters what other measures would facilitate the replenishment of European bat populations.
"In order to decide what further measures are needed, I think that we need to generate an accurate picture of what is happening," she explained. "These directives tend to be quite protective. There are lots of rules about what you are supposed to and what you are not supposed to do, to protect bats. In the UK, for example, you cannot pull a building down if it has a bat roosting in it. You have to go through processes to move the bats, or do it at a certain time of year when the bats aren’t nursing. However, this is only protecting what is there.
"We need to re-establish some of the habitats that bats like. Continued agricultural expansion and human urbanisation aren't good for bats. They are losing the habitats that they need. It would be hard to put a stop to a lot of the habitat loss that goes on. We can’t prevent houses from being built in urban areas, for example. We therefore need to find ways to mitigate the effects of these processes. Measures such as having green roofs in cities and including bat roosts in bridges are positive, but they are not sufficient.
"Lots of projects are currently underway to see how best to build urban areas with bats in mind. We must ensure that bats have what they need to survive in modern Europe."To use the free-of-charge iBatsID tool, click here.