Baker Consultants support an active programme of research aimed at improving ecological survey and analysis techniques. Working in collaboration with a Nottinghamshire based ringing group and using Wildlife Acoustics unattended acoustic recording devices (ARDs), Ecologist Steve Docker is researching male European nightjar Caprimulgus europaeus bioacoustics. Read more
Each year, the Chartered Institute of Ecology and Environmental Management (CIEEM) presents a series of awards to celebrate achievements of both the profession and of individual practitioners working within the ecological and environmental management sector.
The Innovation Award sets out to recognise a successful organisation demonstrating a novel approach to professional practice in any aspect of ecology and environmental management. The award also recognises those who are delivering sustainable benefits for society. Our nomination relates to the research and development of bioacoustics survey skills for the monitoring of western capercaillie (Tetrao urogallus) and European nightjar (Caprimulgus europaeus).
The species the project focused on, western capercaillie and European nightjar, are cryptic species of conservation concern, sensitive to anthropogenic disturbance. The project demonstrated that bird bioacoustics results in increased species detection and financial savings related to reduced survey time, whilst providing a more quantitative assessment of the numbers of breeding nightjar pairs. The applications extend further, providing a minimally intrusive means of measuring nightjar breeding pair numbers at site level, or as part of a national census. This is particularly crucial for nightjars as conventional survey methods may be under-recording this species, conversely, the use of ‘churring’ can lead to over-estimated numbers of breeding pairs. Taken together, this results in serious implications for the conservation of nightjars, which are declining in both numbers and range.
Nightjar spectrogram (frequency plotted against time) showing a series of major (high frequency) phrases and minor (low frequency) phrases
The second stage of the project focusing on capercaillie lek activity was also hugely successful, readily recognising vocalisations using unsupervised software verified by manual analysis, despite challenges due to other bird species and environmental noise. Scottish capercaillie populations are at a critically low level, with the reasons for their decline being complex and not fully understood. This research has the capability of dramatically improving the quality and cost-effectiveness of conventional lek surveys. Previously unmonitored areas can now be feasibly surveyed, and high-quality long-term data can be interrogated for seasonal trends. Results also importantly indicated that traditional lek surveys can in fact cause disturbance to the birds at the lek. Baker Consultants aim to continue using bioacoustics to further aid the spatial and temporal monitoring of capercaillie to benefit conservation management efforts.
Baker Consultants intention for the work is to prove the applicability of bioacoustic methods and increase adoption by conservation bodies and ecological consultancies, which have not yet taken on the practical applications of this valuable tool. This work has been done entirely on a pro-bono basis, principally with Nottinghamshire Wildlife Trust, RSPB, Forestry Commission and Scottish Natural Heritage. Presently, two peer-reviewed papers have been published and made freely available, with more currently in production. Additionally, the UK’s first workshop on bird bioacoustics has been successfully organised, with over 40 participants contributing to the development of a draft bioacoustics survey protocol. This is to be submitted for publication to CIEEMs In Practice soon, to widen awareness of the method, and gain additional feedback from the wider community.
Baker Consultants ecologist Steve Docker has recently completed an innovative research project, which used unattended acoustic recording devices to record the songs produced by male European nightjar Caprimulgus europaeus – a rare bird species that is listed on Annex 1 of the European Community Birds Directive 2009 and is an amber-listed species of conservation concern.
An accurate measure of the number of breeding pairs is essential when evaluating a site for nightjar and Steve’s research set out to identify whether different song types could be used to establish probable breeding. It is thought that acoustic recording technology has not been used for this purpose before for this, or any other, species.The standard survey method used by most surveyors is based upon a co-ordinated count of the number of ‘churring’ males. However, singing is only indicative of possible breeding and does not provide evidence that birds have paired. Furthermore, this method can be labour intensive and may over-estimate the number of breeding pairs because some singing males will be unpaired.
Male nightjars produce two song types, one with an abrupt ending and the other with a distinctive terminal phrase, see Figures 1 and 2.
Using nightjar songs, recorded on automatic devices placed in the field, the study looked at whether this change in vocal structure is linked to pairing status. It revealed that the output of nightjar song with a terminal phrase was significantly greater for probable paired males – and is therefore indicative of a breeding pair being present. This finding has the potential to provide a minimally intrusive means of measuring the number of nightjar breeding pairs at site level or as part of a national census of the species, see Figure 3.
Scan the QR code to listen to a nightjar song (a ‘paired’ male).
In the future Steve aims to publish a scientific paper and also produce a nightjar song type recogniser to support the practical application of this ground-breaking research.
Find out how Baker Consultants are using such technology to support other research projects (Bird Bioacoustics & Nottinghamshire Bat Group) and inform our ecological consultancy projects (Terrestrial & Marine).
To find out more about this nightjar bioacoustics research please email firstname.lastname@example.org
Our nomination relates to the research and development of bioacoustics survey skills for the monitoring of European nightjar, a species of bird often perceived as being in conflict with wind farm developments and operations. Nightjars are widespread in Wales and can be a considerable constraint to development as they receive special legal protection.
Bioacoustics and the nightjar
Traditional survey methods used to establish the presence of nightjars, a bird both elusive and cryptic in behaviour, are expensive and can necessitate walked transect surveys, tape luring surveys and radio tracking to map their distribution and nest sites.
During 2013 and 2014, we carried out research into the use of bioacoustics survey methods as an alternative to conventional methods.
Andrew Baker, Managing Director of Baker Consultants, says: “At their basic level, bioacoustics surveys involve placing recording devices out in the field, often for extended periods, and recording animal sounds. This has many advantages over conventional surveys techniques, as a large amount of data can be gathered over an extended period of time as recording devices are left unattended for up to three months. Such data is critical, making it possible to establish whether records of nightjar are simply those passing through or those with established territories on the site.This can provide crucial information regarding whether a development gains approval. Furthermore, the costs of bioacoustics surveys are much lower than conventional methods”.
Baker Consultants also funded research by Dr Mieke Zwart as part of a joint project led by Dr Mark Whittingham of Newcastle University. The research proved that the use of bioacoustics was much more effective than established methods and was published as a peer-reviewed paper. This established the value of bioacoustics in nightjar surveying and paved the way for wider use of this cost-effective survey technique. There is also considerable potential for further development of this technique to allow a more detailed understanding of the use of a site by nightjar and other important species.
The Wales Green Energy Awards are in their third year, and organised by RenewableUK Cymru to celebrate the success and achievements of the green energy industry in Wales. The award winners will be announced on Friday 6 November in Cardiff.
David Clubb, Director of RenewableUK Cymru, said: “We are always delighted by the quality of submissions for the Wales Green Energy Awards, and this year is no exception. Each of the shortlisted individuals or organisations should feel extremely proud of what they have achieved over the last 12 months, often in the face of challenging political and policy decisions.”
Baker Consultants and Wales
Baker Consultants has been providing ecological services to projects throughout Wales for a number of years and this year we consolidated our presence with an office in Swansea, following increased demand in the region and growth in the renewables sector. Read more in our article here.
Contact a member of our Welsh team today to discuss your project
At Baker Consultants, we support an active programme of research aimed at improving ecological survey and analysis techniques. As part of this, our Ecologist Steve Docker is currently working in collaboration with a Nottinghamshire based ringing group undertaking research into European nightjar (Caprimulgus europaeus) vocalisations using automated acoustic sampling.
When evaluating a site for European nightjar, which is a ‘red-listed’ species of conservation concern, an accurate measure of the number of breeding pairs is essential. The standard survey method is based upon counting the number of singing ‘churring’ males. However, this is only indicative of possible breeding and does not provide conclusive evidence that birds have paired.
Experienced field workers have noted that the structure of nightjar vocalisations appears to be modified when a male has paired with a female and this current research project is investigating whether this change in vocal structure can be detected by automated acoustic sampling, represented visually on a spectrogram. To our knowledge this is something that has not been attempted before for this, or any other, species.
Spectrograms are a visual means of representing sound and contain a great deal of information. This project involves recording male nightjar song and testing for a relationship between spectrogram variables and breeding status. It is hoped that this work will form the basis of an improved survey method for European nightjar.
Steve said: “As I have a long-term interest in birdsong, especially the concepts of ‘song types’ and ‘vocal individuality’, I am delighted to be working on this research project, which will form the basis of my MSc dissertation. It is particularly exciting that we are applying technology in such an innovative way and that we will hopefully be able to improve standard nightjar survey methods from the basis of our research”.
Last year, Baker Consultants working with Dr Mieke Zwart and Professor Mark Whittingham of Newcastle University showed how bioacoustics is a much better technique for surveying nightjar than the standard survey method.
Bioacoustic recorders could provide us with vital additional information to help us protect rare and endangered birds, such as the European nightjar. Research, led by Newcastle University, found that newly developed remote survey techniques were twice as effective at detecting rare birds as conventional survey methods.
Using automated equipment to record nightjars at dawn and dusk, when the birds are most active, the team found a 217% increased detection rate of the nightjar over those carried out by specialist ornithologists. Published this month in the prestigious academic journal Public Library of Science One (PLOS ONE) (article available here), lead author Mieke Zwart said the findings suggest that automated technology could provide us with an important additional tool to help us survey and protect rare birds.
“The results of this research will help conservationists monitor endangered species more effectively,” explains Mieke, who carried out the research as part of her PhD, supported by Baker Consultants Ltd and Wildlife Acoustics Inc. “The European nightjar, for example, is only active at night and is very well camouflaged, making it difficult to detect using traditional survey methods. Using bioacoustics techniques we can more accurately build up a picture of where these birds are, population numbers, movement and behaviour.”
The European nightjar – Caprimulgus europaeus – is a migratory species protected under the Birds Directive (Directive 2009/147/EC) and in the UK by the classification of Special Protection Areas (SPAs). Nesting on lowland heath, such as parts of Sherwood Forest and Thames Basin Heath, the nightjar can be negatively affected by developments including housing. Due to this, as part of the planning process, developers must now provide data on presence and abundance of nightjar and provide mitigation plans to prevent their disturbance before planning applications will be considered.
Traditional bird survey methods involve specialist ornithologists conducting field surveys to identify and count the birds they encounter. However, these are time-consuming, must be performed by experts, and could be inaccurate when surveying species that are difficult to detect.
Bioacoustics is the science of recording of wildlife sounds and processing that data to provide information on species numbers, movement or behaviour. Using automated audio recorders and analysis software, the technology is ‘trained’ to automatically recognise the calls of individual species, in this case the nightjar. Remote recorders were deployed at specific sites and the results were compared against observations from standard human field surveys of the same sites.
Andrew Baker, co-author of the paper, said: “This is a key piece of research that has demonstrated how effective bioacoustics techniques can be for providing ecological data. This research has challenged conventional methods and could be applied to a wide range of species to give more accurate, objective data on bird numbers and distribution. The study has implications for a range of other species, including black grouse (Tetrao tetrix), capercaillie (Tetrao urogallus) and woodlark (Lullula arborea). This is especially important when information on species presence and abundance is used to inform conservation projects or development plans.”
Read more about our latest nightjar bioacoustics project here.
Source Information: “The use of automated bioacoustic recorders to replace human wildlife surveys: An example using nightjars.” Mieke C. Zwart, Andrew Baker, Philip J. K. McGowan, Mark J. Whittingham. PLOS ONE, July 16, 2014
Mieke Zwart, PhD student, School of Biology, Newcastle University. Tel: 07580 362783; email: email@example.com
Andrew Baker, Managing Director of Baker Consultants Ltd and a co-author of the paper. Tel: 07590 122969; email:firstname.lastname@example.org
Louella Houldcroft, Senior Communications Manager, Newcastle University. Tel: 0191 208 5108/07989 850511; email:Louella.email@example.com
This work was part-funded by Wildlife Acoustics, Inc who also provided the recording devices and software to process the recordings.