A significant proportion of our work could be described as ‘rescue’ jobs, where a client approaches us to pick up from another ecologist’s work, because for whatever reason they cannot continue with the project. Mostly, it is simply that the previous consultant does not feel comfortable appearing as an expert witness at a public inquiry (it’s not for everyone), or they do not have the specialist knowledge for a particular aspect of the work.

In all cases, a thorough review of the previous ecologists’ work is conducted to ensure that nothing has been missed. The most common failing that we find is in regards to bat surveys. It seems that many ecologists are using now out-dated equipment to capture survey data including heterodyne, time expansion and zero crossing detectors. This creates a series of problems: the data collected is inaccurate as it doesn’t capture accurate GPS readings or misses bat activity; and data processing is more time-consuming, can lead to misidentification of bat species, and therefore will be unrepresentative of the site population. More concerning is when modern equipment is used but then incorrectly analysed. This effectively loses a large proportion of the collected data, fails to follow best practise, and can cause serious implications further in the project.

This is a highly technical issue, of which most clients may be unaware. However, incorrect use of bioacoustics technology can pose a significant risk to a project, especially in obtaining planning permission or as part of a Habitat Regulations Assessment. As industry leaders, Baker Consultants uses the latest full spectrum detectors which capture all signal information and output it in real-time. The data collected is highly detailed, suitable for analysis using automated bat recognition software which is manually validated by experts. In Layman’s terms, large amounts of valuable data can be collected and analysed cost-effectively and accurately. This method undeniably produces better results for the project long-term.

Figures 1 and 2 further highlight the differences between zero crossing and full spectrum data. The two methods processed the same bat data record, however, zero crossing (Figure 1) failed to confidentially identify the Myotis bat species and the social calls from the soprano pipistrelle (Pipistrellus pygmaeus).

 

Figure 1. Bat data analysed in Kaleidoscope (Wildlife Acoustics Inc.) using zero crossing output; soprano pipistrelle identified.

 

Figure 2. Bat data analysed in Kaleidoscope (Wildlife Acoustics Inc.) using full spectrum output; soprano pipistrelle with social calls and Myotis species identified.

 

So how do you ensure that your ecologist is using the correct technical equipment to protect the outcome of your project? Simple, just ask! Specify full spectrum recording in the work brief both at the recording and analysis stage. The use of time expansion, heterodyne or zero crossing devices on your project should not be accepted. Technology has moved on, and you need to ensure that your ecologist has moved on with it.