Ewch i’r prif gynnwys
Yr Athro William O.C. Symondson

Yr Athro William O.C. Symondson


Ysgol y Biowyddorau

+44 (0)29 2087 5151
+44 (0)29 2087 4116
Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX, Adeilad Syr Martin Evans, Rhodfa'r Amgueddfa, Caerdydd, CF10 3AX


Research overview

I am interested in the dynamics of predator-prey interactions and how predators make choices between competing prey species. Most of our work has been on invertebrates in arable crops centred upon two trophic interactions: carabid beetles vs. slugs, and linyphiid spiders vs. aphids. A major interest has been in how non-pest prey affect predator-target prey interactions. Current work uses a combination of network analyses, SADIE and Monte Carlo simulations to examine the temporal and spatial interactions between predators and many different prey simultaneously. This work has been facilitated by the development of PCR-based system for detecting prey DNA in predators. Most recently we have been using next generation sequencing to look at complete dietary ranges of invertebrates and vertebrates in both temperate and tropical habitats. Related work includes phlogenetics (earthworms, molluscs, planthoppers), intraguild predation, scavenging, vertebrate diets (reptiles, birds, mammals), microarthropods predating nematodes and spider responses to insect vibrational communication signals.

Research division

Organisms and Environment






















My interest is in the dynamics of predator-prey interactions involving generalist predators (and recently) herbivores. The choices made by such predators are complex and the result of interactions between a range of spatial and temporal biotic and abiotic factors. Given the limitations of laboratory-based prey choice experiments we concentrate instead on developing techniques for measuring the strengths of trophic interactions directly in the field. We were amongst the first to realise the potential of PCR to amplify prey DNA from field-caught predators and are at the forefront of developments in this field.  Initially we developed multiplex systems to analyse each predator for multiple prey targets in a single PCR step. More recently we have been using next generation sequencing (NGS - 454 and Ion Torrent) to look at complete diets. 

Current and recent projects

  • A phylogenetic analysis of common earthworm species revealing extraordinary levels of cryptic diversity, plus development of molecular markers for different lineages/species of earthworm to track predation on them by invertebrate and vertebrate predators.
  • Analysis of interception by predators of vibrational sexual communication signals between planthoppers and confirmation of predation in the field using molecular diagnostics (with the National Institute of Biology, Ljubljana).Analysis of intraguild predation in arable crops, including a range of predators feeding or parasitoids, carabids feeding of spiders and spider-spider interaction.
  • Analysis of intraguild predation in arable crops, including a range of predators feeding or parasitoids, carabids feeding of spiders and spider-spider interaction.
  • Competition between the alien Asian Musk Shrew and the rare Telfair's Skink on a Mauritian island analysed using NGS (with Durrell Wildlife and the Mauritian Wildlife Foundation).
  • Analysis of herbivory by giant tortoises introduced as an analogue species to restore ecosystem function on a Mauritian island.
  • Analysis of the diets of seabirds during migration and nesting (petrels and albatross).
  • Analysis of the diets of bats in European and tropical habitats using NGS (e.g. comparing diets of bats in rainforest vs. oil palm plantations).
  • Analysis of food webs in farmland: a) in rivers running through intensive vs. extensive farming systems; b) exploitation of patchy landscapes by farmland birds (with BTO).
  • Analysis of the diets of British reptiles.

I have a particular interest in slugs and their natural enemies. Advice on slug control in the garden.

Current staff

Postdoctoral researchers

  • Dr Victoria San Andres (Spanish Government Fellowship, working on intraguild predation - she has left but still writing papers)
  • Dr Meta Virant-Doberlet (from the National Institute of Biology, Ljubljana, working on interception and exploitation of intraspecific vibrational communication between insects by generalist predators and on possible hybrid speciation in Aphrodes leafhoppers)
  • Prof Josep Pinol (on sabbatical from the University of Barcelona, working here on analysis of predation by spiders and carabids in cereal fields using next generation sequencing - recently left but papers being completed)
  • Dr Elizabeth Clare now at Queen Mary College, a visitor to my lab while developing next generation sequencing of prey DNA in bat faeces.

PhD students

  • Ms Azniza Mahyudin ("Analysis of the population genetics and diets of cave-roosting bats in Sabah")
  • Ms Caitlin Pearson ("Impacts of agricultural land use or river ecosystem functioning, as mediated through trophic interactions")
  • Ms Silke Waap ("DNA barcoding in a remote marine environment", analysing the diets of sea birds using next generation sequencing)
  • Ms Jennifer Stockdale (Using environmental genomics to track habitat use by birds exploiting heterogeneous landscapes)
  • Ms Lenka Petrakova (Czech student visitor developing NGS to analyse the diets of termite-eating spiders)

Grant awarding bodies

Current funding

  • Natural Environment Research Council
  • Malaysian Government
  • Portuguese Government
  • British Trust for Ornithology
  • Durrell Wildlife Conservation Trust

Funding for other recent research

  • Croatian Government
  • Environment Agency
  • Department of the Environment, Food and Rural Affairs
  • Countryside Council for Wales

Current and recent collaborations

  • Durrell Wildlife Conservation Trust
  • Mauritian Wildlife Foundation
  • Bristol Zoological Gardens
  • Centre for Genomics Research, Liverpool University
  • National Institute of Biology, Ljubljana, Slovenia
  • University of Bergen, Norway
  • University of Barcelona, Spain
  • University of Kentucky
  • United States Department of Agriculture
  • National Museum of Wales, Cardiff
  • University of Bristol
  • Game & Wildlife Conservation Trust
  • Institute of Arable Crops Research, Rothamsted
  • Masaryk University, Brno, Czech Republic

Proffiliau allanol

Unedau Ymchwil