Patterns and process in population trends of UK herpetofauna

CASE award with the ARC Trust (ISAAC_KCEH19ARIES)

Patterns and process in population trends of UK herpetofauna

CASE award with the ARC Trust (ISAAC_KCEH19ARIES)

Project Description


Dr Nick Isaac (Centre for Ecology and Hydrology)

Prof Richard Griffiths (University of Kent)

Dr John Wilkinson (ARC Trust)

Angela Julian (ARC Trust)

Kate Risely (British Trust for Ornithology)

Scientific background

Reliable estimates of biodiversity are constrained by an inability to produce robust estimates of nationwide status, trends and threats for many cryptic taxa. Effective decision-making therefore requires (1) a better balanced assessment of biodiversity; and (2) collation and analysis of ‘messy’ species data that are collected using a variety of protocols and stakeholder groups.

Anecdotal evidence points to declines in many of the UK’s amphibians and reptiles (or herpetofauna), particularly in formerly widespread species such as the adder and common toad. The National Amphibian and Reptile Recording Scheme (NARRS) was designed to provide evidence on trends in UK herpetofauna, but has been unable to deliver substantive insights into drivers of these trends. Fortunately, statistical tools have now emerged that are capable of providing robust trends from unstructured data, including citizen science records.

Research methodology

This project will bring together existing datasets from a range of organisations into a common modelling framework, based on a hierarchical Bayesian occupancy-detection model. These outputs will be used  to:

  1. Reveal national status and trends from disparate data (including NARRS)
  2. Determine the drivers of trends in distribution and abundance
  3. Forecast trends under scenarios of future change
  4. Advise on the design of an integrated monitoring portfolio


The student will receive a comprehensive training experience, covering a broad range of analytical skills including Bayesian statistical techniques for spatio-temporal modelling using citizen science data, as well as transferable skills including stakeholder engagement and knowledge exchange.

Person specification

The successful candidate will have at least a 2:1 degree in a relevant subject and be capable of demonstrating good numeracy and an aptitude for modelling. Experience of UK wildlife conservation, especially reptiles and amphibians, would be an advantage. Good interpersonal and communication skills will be required as the project will involve engagement with a diversity of stakeholder groups.

The successful candidate will be registered for a PhD in the Unviersity of Kent’s School of Anthropology and Conservation.

In this short video, Professor Richard Griffiths discusses amphibian and reptile surveys in the UK and how statistical models can help in their design and analysis:


  • Isaac, NJB et al. (2014) Statistics for citizen science: extracting signals of change from noisy ecological data. Methods Ecol. Evol. 5, 1052–1060
  • Griffiths, R.A., Foster, J., Wilkinson, J. & Sewell, D. (2015). Science, statistics and surveys: a herpetological perspective. Journal of Applied Ecology 52: 1413-1417.
  • Biggs, J., Ewald, N., Valentini, A., Gaboriaud, C., Dejean, T., Griffiths, R.A., Foster, J., Wilkinson, J.W., Arnell, A., Brotherton, P., Williams, P. & Dunn. F. (2014). Using eDNA to develop a national citizen science-based monitoring programme for the great crested newt (Triturus cristatus). Biological Conservation 183:19-28.
  • Pagel, J., Anderson, B.J., O’Hara, R.B., Cramer, W., Fox, R., Jeltsch, F., Roy, D.B., Thomas, C.D. & Schurr, F.M. (2014) Quantifying range-wide variation in population trends from local abundance surveys and widespread opportunistic occurrence records. Methods in Ecology and Evolution, 5, 751–760.
  •     Burns, F., Eaton, M.A., Barlow, K.E., Beckmann, B.C., Brereton, T., Brooks, D.R., Brown, P.M.J, Al Fulaij, N., Gent, T., Henderson, I., Noble, D.G., Parsons, M., Powney, G.D., Roy, H.E., Stroh, P., Walker, K., Willkinson, J.W., Wotton, S.R. & Gregory, R.D. (2016) Agricultural management and climatic change are the major drivers of biodiversity change in the UK. PLoS ONE 11(3): e0151595. doi:10.1371/journal.pone.0151595

Open for applications

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