Sounding them out: a unique conservation tool for monitoring bush-crickets

No.:  January 2017 - 02
January 2017
Speckled Bush-cricket by Tom Housley

New research led by British Trust for Ornithology (BTO) and published today in the international journal Methods in Ecology and Evolution, shows how existing bat monitoring could improve our understanding of bush-crickets.

Bush-crickets are a little-known group of insects that inhabit our marshes, grasslands, woods, parks and gardens. Some may be seen in the summer when they are attracted to artificial lights, but as most produce noises that are on the edge of human hearing, we know little about their status. There are suggestions that some bush-crickets may be benefiting from climate change, while others may be affected by habitat changes. But how to survey something that is difficult to see and almost impossible to hear?

Advances in autonomous recording devices are transforming our understanding of bats, but the large-scale deployment of such devices has the potential to also improve our understanding of other species groups, which produce loud and characteristic sounds.

The original objective of BTO’s bat surveys was to trial the recording of bat activity using passive real-time detectors, to gauge the willingness of members of the public to engage in bat monitoring at a large scale, and to determine the suitability of automated identification routines for processing large volumes of citizen-science collected bat recordings. It soon became clear that bush-crickets were also being recorded in large numbers.

Working with the Museum of Natural History in Paris and Natural England we have developed a computer algorithm to identify the sounds made by different species of bush-crickets. After carefully validating these state-of-the-art methods using field recordings in Norfolk, we can now examine daily activity patterns of different species of bush-cricket and determine where different species live. The speckled bush-cricket for example, pictured above, would normally be easy to overlook because it occurs in vegetation and makes sound (stridulates) at a frequency too high for humans to hear. With over 260,000 recordings of this species collected through bat surveys in Norfolk, we know that this species is common and widespread, with a distribution that extends into Norwich. At the other extreme, great green bush-cricket, previously known from only a few locations in Norfolk, was recorded at two locations, of which one was a new site for this species.

Dr Stuart Newson, lead scientist on the project at the BTO, said:

“There is a huge potential to take advantage of established large-scale bat monitoring to also collect high-quality monitoring data for bush-crickets. It is likely that large volumes of information on bush-crickets are already being collected incidentally by bat workers using static detectors, but is at best noticed and ignored.”

Dr Yves Bas, researcher at the Muséum National d'Histoire Naturelle in Paris said: 

“This is a really important step towards the development of automated sensor networks, which are likely to play an important role in the future monitoring of biodiversity”.

Ash Murray, Senior Reserves manager at Natural England, said: 

“As the government’s adviser for the natural environment in England, Natural England knows how critical monitoring is to the long-term protection of our species. This new technology, and BTO’s innovative methods of enabling huge numbers of the public to use it, are inspirational for wildlife conservation here in the UK”.

Reference: Newson, S.E., Bas, Y., Murray, A. & Gillings, S. (2017). Potential for coupling the monitoring of bush-crickets with established large-scale acoustic monitoring of bats. Methods in Ecology and Evolution. Online early.

Contact Details

Dr Stuart Newson
(British Trust for Ornithology)
Office: 01842 750050
(9am to 5:00pm)
Email: stuart.newson [at] bto.org

Dr Simon Gillings
(British Trust for Ornithology)
Office: 01842 750050
Email: simon.gillings [at] bto.org

 Paul Stancliffe
(BTO Press Officer)
Office: 01842 750050
(9am to 5:00pm)
Mobile: 07585440910 anytime
Email: press [at] bto.org

Images are available for use alongside this News Release. Please contact images [at] bto.org quoting reference January 2017 - 02

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Notes to editors

The British Trust for Ornithology (BTO) is the UK’s leading bird research organisation. Over 40,000 birdwatchers contribute to the BTO’s surveys. They collect information that forms the basis of conservation action in the UK. The BTO maintains a staff of 100 at its offices in Thetford, Stirling, Bangor (Wales) and Bangor (Northern Ireland), who analyse and publicise the results of project work. The BTO’s investigations are funded by government, industry and conservation organisations. www.bto.org

The analyses was largely based on data collected through the Norfolk Bat Survey (www.batsurvey.org) which is led by BTO in partnership with NBIS, National Trust (Sheringham Park), Wildfowl and Wetlands Trust (Welney Wetland Centre), Wheatfen (Ted Ellis reserve), Sculthorpe Moor (Hawk & Owl Trust), Broads Authority (How Hill), RSPB (Titchwell) and Norfolk Libraries and Information Service (Aylsham, Hethersett, Caister, Attleborough, Watton, Swaffham, Dereham, Downham Market, Gaywood, Long Stratton and Wells libraries), Dinosaur Adventure (Lenwade), Brandon Country Park, The River Waveney Trust (River Waveney Study Centre at Earsham), Suffolk Bat Group, the Pennoyer Centre, the Breckland Society, and the Little Ouse Headwaters Project.
 
This work was funded through a BTO Research Fellowship awarded to Dr Stuart Newson and made possible through a legacy gift from Maxwell Hoggett. The work at Dersingham Bog was funded by Natural England through the Natural England Innovation Fund.