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Dr Robert Thomas

Dr Robert Thomas

Senior Lecturer

+44 (0)29 2087 6653
+44 (0)29 2087 4116
C5.11, Sir Martin Evans Building, Museum Avenue, Cardiff, CF10 3AX
Available for postgraduate supervision


My research group studies animal behaviour in changing environments. The environmental changes that we study range from long-term climate changes, through seasonal and daily changes, to the sudden appearance of a potential predator or an unfamiliar type of food. This work falls under four main headings, though there is plenty of overlap between these topics.

Climate change biology

Focusing on major study systems that use migratory birds as sensitive bio-indicators of climate-driven changes in trophic relationships.

  • The Storm Petrels –the smallest of the seabirds, spending most of their lives on the open ocean. Our studies include work on the European Storm Petrel, Leach's Storm Petrel, and the Band-Rumped Storm Petrel species complex, including seasonally-segregated populations/species in the Azores and St Helena.
  • The Northern Wheatear –an upland species with the most extreme trans-oceanic migration of any songbird
  • Reed-bed warblers (Reed Warblers and Sedge Warblers) –a pair of congeneric migrants with contrasting migration strategies
  • The Pied Flycatcher -a rapidly-declining songbird of the Welsh oak woodlands
  • The Barn Swallow -familiar herald of summer in a rapidly changing climate
  • The European Nightjar -specialist predator of nocturnal moths

An online talk about some of my current climate change research is available on Youtube.

Sensory constraints on behaviour

  • Eye design in birds and visual constraints on behaviour
  • Impacts of light and noise pollution on wildlife
  • Automated acoustic monitoring and identification of bat echolocation calls as a monitoring tool

Dietary wariness and foraging ecology

  • Novel-food wariness in birds and fish, and its evolutionary consequences
  • Strategic regulation of energy reserves in wild birds
  • Diet choice and foraging ecology
  • Co-author/curator of the Wikipedia page for Dietary Conservatism.

Impacts of human activities on wild animals


I did my first degree (MA, BA) in Zoology and Ecology at Cambridge University (graduating in 1993), and my D.Phil. at the University of Sussex (graduating in 1997). After a short period as assistant warden at A Rocha Bird Observatory in Southern Portugal, I moved to the Centre for Behavioural Biology at Bristol University in 1998 to take up a NERC-funded post-doctoral position. In 2002 I was awarded a NERC Post-doctoral Research Fellowship, which I brought to Cardiff School of Biosciences.  I was appointed to a lectureship here in 2006 and am now a Senior Lecturer.

Positions and responsibilities

  • Co-Director of Eco-explore Community Interest Company.
  • Council Member of the Association for the Study of Animal Behaviour (ASAB, 2009-2016).
  • Education Secretary of the Association for the Study of Animal Behaviour (2011-2016).
  • Member of the Ethics Committee of the Association for the Study of Animal Behaviour (2006-2013, acting Secretary 2007, 2009).
  • Member of the Cardiff University Ethics Committee covering non-ASPA research (2019-present).























  • PhD student supervision (see "supervision" tab)
  • PhD assessor / examiner
  • Data analysis training (see below)


  • Data Science (module leader)
  • Survey methods: Ornithology
  • Personal tutor
  • MSc project supervisor

MBiol / MRes

  • Project supervisor
  • Research methods: Ornithology

Final year

  • Conservation Biology
  • Global Change Biology
  • Final-year project supervision

Professional Training Year (PTY)

I provide a substantial contribution to Cardiff School of Biosciences work-placement programme for undergraduates, normally supervising 2-3 PTY students per year as Cardiff University academic supervisor, plus 1-3 placements per year as Eco-explore co-director.

Second year

  • Animal Diversity & Adaptation
  • Brain & Behaviour (assessment leader)

Field courses

  • Ecological Survey Methods (Kenfig and Parc Slip Nature Reserves, South Wales)
  • Behaviour and ecology (Cardiff)

First year

  • Animal Behaviour
  • Sexual selection
  • Ecological survey methods

Data analysis and statistics

I run regular courses in Data Analysis through the year. for staff and students, including courses for PhD students (NERC GW4+ DTP), the Royal Society for the Protection of Birds (RSPB), and the Student Conference for Conservation Science (SCCS) at Cambridge University.

General teaching / learning activities

  • Various activities relevant to the Zoology degree scheme, including supporting the Cardiff University Ornithological Scociety ("Bird Club"), and the Wildlife and Conservation Society ("Wildsoc")
  • Personal tutor


Climate change biology

What are the biological impacts of climate change? My research group is investigating the effects of climate on individuals, populations and ecological processes - particularly how such effects may be mediated by the behaviour of individual animals. Our current work in this field focuses on major study systems that use migratory birds as sensitive bio-indicators of climate-driven changes in trophic relationships.

Effects of climate changes on trophic relationships in marine ecosystems

The body mass regulation behaviour of the smallest Atlantic seabird (the European storm petrel) changes between years in response to climate-driven changes in sea temperatures. Together with Renata Medeiros and collaborators, we coordinate a long-term monitoring project investigating how these changes are mediated by changes in the marine food webs on which storm petrels rely.

The speciation of the band-rumped storm petrel "super-species" is the first documented example of sympatric speciation in a bird (and indeed in any tetrapod). Renata Medeiros, Hannah Hereward, Annalea Beard and collaborators are investigating how diet and foraging ecology varies between sibling-species breeding in different seasons and locations and years, with the aim of understanding how foraging traits are linked to speciation events.

Effects of climate changes on migrant birds

Migration is one of the major challenges to survival faced by many animals, and the availability of food and other resources along the migration route is of critical importance to successfully completing the journey. Furthermore, climate may impact individuals in different ways in different parts of the annual cycle (breeding grounds, migration stopover sites and wintering areas). Together with Adam Seward, James Vafidis, Rich Facey, Jez Smith, Mike Shewring, Sarah Davies and collaborators, we combine observational studies in the field, lab and field mesocosm experiments, experimental manipulations of food availability and analyses of long-term climate and bird ringing databases, to examine the effects of climate changes on breeding behaviour, reproductive success, migration decisions, wintering ecology and annual survival of migrant songbirds. The species studied to date are primarily northern wheatears and various species of reedbed warblers, with a new project on barn swallows now underway. This work is carried out at breeding locations (Wales for warblers, flycatcher, swallows and nightjars, Shetland and Greenland for wheatears), migration stopovers (Portugal and Shetland) and wintering areas (Senegal).

Sensory constraints on behaviour

How do animals decide when to be active? My research collaboration with Alex Pollard, Rhian Newman and others focuses on the role of eye design and visual constraints in an animal's behavioural decisions, particularly under varying light levels at twilight and at night. Specific projects have examined eye size and the timing of singing (in songbirds) and foraging (in shorebirds), as well as aviary and field studies of the impacts of light pollution, using night-singing in European robins and activity of aquatic organisms as case-studies.

Dietary wariness and foraging ecology

When a forager encounters an unfamiliar object, it must decide whether to eat it and risk being poisoned (if it is toxic) or avoid it and risk missing out on a valuable food source (if it is palatable). Foragers generally show brief aversions to novel objects (neophobia) but some individuals also show a much more persistent aversion to eating novel foods (dietary conservatism), which can last for weeks or even years. In collaboration with Nicola Marples, Jo Cable and others, we investigate the function, control and evolutionary consequences of these aspects of dietary wariness, in a range of taxonomic groups –primarily birds and fish. Related to this, I am also interested in the foraging decisions underlying the strategic regulation of energy reserves in foraging birds, over minutes, days, seasons and years.

Impacts of human activities on wild animals

Large numbers of wild animals are captured, handled, often marked for individual identification, and released in the course of scientific research and conservation monitoring programmes. Surprisingly, little is known about the effects of capture and handling on the animals themselves. We are investigating the impact of capture and handling on the body mass regulation and foraging behaviour of animals throughout the annual cycle, and on breeding behaviour and fitness parameters. This work has implications for the design and implementation of ethical field studies on wild animals. Other studies of human impacts include evaluating and minimising the impacts of eco-tourism, and monitoring habitat use and foraging ecology of birds and other animals, in areas earmarked for –or currently undergoing- development.


Current PhD students

Current Masters students

  • Sarah Morgan (MPhil): Parasite communities of seabird communities. Sarah is also the Education Officer for Eco-explore Community Interest Company ( ).

Associated Researchers

Stephen Davison


BSc (Hons.) Leeds University. MSc Salford University. MBA Open University. BA (Hons.) University of Wales Lampeter.

Research Interests: My research interests are bats, in particular the ecological aspects of the woodland bats of South East Wales.


Stephen P. Davison & Robert J. Thomas.  2017. Apparent Spring Swarming Behaviour of Lesser Horseshoe Bats (Rhinolophus hipposideros). Journal of Bat Research and Conservation 10 (1).

Stephen Davison 2021. Lunar Phobia in British Swarming Bats.  British Island Bats vol 2 P174 – 185.

Ashoka Ranjeewa

Research webpage:


Ranjeewa A. D. G., Pastorini J., Isler K., Weerakoon D. K., Kottage H. D., Fernando P.; Decreasing reservoir water levels improve habitat quality for Asian elephants. (Preparing the manuscript)

Ranjeewa A. D. G., Tharanga Y. J. S., Sandanayake G. H. N. A., Perera B. V., & Fernando P. (2015) Camera traps unveil the enigmatic crop raiders in Udawalawe, Sri Lanka. Gajah 42, 7-14.

Ranaweera E., Ranjeewa A. D. G., Koun Sugimoto (2015). Tourism induced disturbance on wildlife in protected areas; A case study of free ranging elephants in Sri Lanka. Global Ecology and Conservation, 4, 625–631.

de Silva S., Ranjeewa A. D. G., Weerakon D. K. (2011) Demography of Asian elephants (Elephasmaximus) at Udawalawe national park, Sri Lanka, based on identified individuals. Biological conservation, 144, 1742-1752.

de Silva S., Ranjeewa A. D. G., & Kryazhimskiy S. (2011) The dynamics of social networks among female Asian elephants. BMC Ecology, 11, 17.

Nils Bouillard

Nils offers a range of services in bat research, training and consultancy:

Deji Bolade
Sarah Long
Jack Devlin
Ben Porter

Past projects

Completed PhD students:

1. Dr. Alex Wilson: Eye design in birds and visual constraints on behaviour. Alex is now Senior Ecologist at Mott MacDonald Ltd., and is Managing Director of Eco-explore Community Interest Company

2. Dr. Jenny Clapham: Biodiversity value of biomass crops. Jenny now works in healthcare services in the USA and UK.

3. Dr. Joe Woodgate: Developmental stress and mate choice behaviour in birds. Joe was a post-doctoral researcher at the University of Sussex and is now at Queen Mary, University of London

4. Dr. Loys Richards: Dietary wariness in fish. Loys now works in healthcare services at the University Hospital of Wales.

5. Dr. Renata Medeiros: Diet and foraging ecology of Storm Petrels. Renata is now a Lecturer in statistics at Cardiff Dental School, and is actively involved in supervision of seabird research students at Cardiff School of Biosciences

6. Dr. Leila Duarte: Impacts of capture and handling on wild birds. Leila now works in conservation in Portugal.

7. Dr. Adam Seward: Impacts of climate change on the northern wheatear. Adam is now a professional photographer and conservation biologist, based in Scotland

8. Dr. Jim Vafidis: Impacts of climate change on wetland songbirds. Jim is now Senior Lecturer in Natural History at the University of the West of England, and is co-Director of Eco-explore Community Interest Company

9. Dr. Rhian Newman: Impacts of artificial light at night on freshwater organisms. Rhian is now a Lecturer in Biology at the University of South Wales

10. Dr. Jen Stockdale: Diet, foraging ecology and breeding productivity of famland songbirds. Jen is now a Lecturer in Biology at Nottingham University

11. Dr. Farina Othman: Behaviour and conservation of Bornean forest elephants. Farina has established an NGO working to address human-elephant conflicts in Borneo.

12. Dr. Jez Smith: Impacts of climate change on a rapidly declining woodland songbird -the pied flycatcher. Jez is now a Lecturer in Natural History at the University of South Wales, and is a co-Director of Eco-explore Community Interest Company.

13. Dr. Amy Schwartz: The ecology of roadkill Amy now works as an ecological consultant, expert bat rehabilitator and all-round natural history legend.

14. Dr. Sophie-lee Williams: Golden and White-tailed Eagles in Wales; past, present and future    Sophie is now the Welsh Eagle Reintroduction Officer with the Durrell Institute.

15. Dr. Sarah Davies: Diet and foraging ecology of reedbed warblers. Sarah is now Senior Research Officer with the Wildfowl and Wetalnds Trust.

16. Dr. Alex McCubbin: Mate choice among storm petrels. Alex is now a Senior Laboratory Technician at Cardiff University.

17. Dr. Richard Facey: Impacts of local weather conditions on the seasonal fecundity of Barn Swallows. Rich is Ornithologist with Natural Resources Wales and has a long track record of work in the applied conservation sector .

18. Mike Shewring: Impacts of climate change on upland bird communities, focusing on the European Nightjar. Mike now works for the Royal Society for the Protection of Birds on upland ecology topics, and runs his own successful environmental consultancy.

19. Hannah Hereward: Conservation biology of two sibling-species of storm petrels breeding on the Azores Hannah now works for the British Trust for Ornithology's Cymru team.

20. Zoe Deakin: Monitoring the breeding biology and foraging ecology of storm petrels in the North Atlantic Zoe now works for the Royal Society for the Protection of Birds' Seabird Team.

Recently completed Masters students


  • Megan Abram (MPhil): birds of prey in the landscape of mid-Wales
  • Komal Gogi (MSc): breeding success and failure in Pied Flycatchers 
  • Rosie Walkley (MSc): foxes in Cardiff
  • Shannon Filer (MSc): bat diversity and habitat selection in mid-Wales


  • Georgia Isted (MBiol): Movement ecology of Ferruginous Hawks in North America.
  • James Douglas (MBiol): Foraging ecology of peregrine falcons and other raptors.
  • Eleanor Burgess (MSc): Evolution of song differences among species of storm petrels.
  • Freja McCall-Stephenson (MSc): Behaviour and ecology of woodland bats.
  • Tabitha Gibbons (MSc): Climate impacts on the breeding productivity of Golden Eagles.
  • Laura Robinson(MSc): Light pollution and foraging behaviour of urban-living Peregrine Falcons.
  • Tom Allison (MSc): Impacts of light and noise pollution on singing behaviour of Passerine birds.


  • Matthew Collins (MBiol): Golden and White-tailed Eagles in Wales.
  • Laura Astbury (MSc): Behaviour, ecology and conservation of Monteiro's Storm Petrel.
  • Molly Laban (MSc): Conservation biology of the Pied Flycatcher.
  • Ed Drewitt (MSc): Post-fledging dispersion of urban peregrine falcons.


  • Jack Devlin (MRes): Impacts of Pheasants on invertebrate communities in upland Wales.
  • Zoe Jones (MRes): Birds of prey in the modern Welsh landscape.
  • Sam Langdon (MBiol): Birds of prey in the modern Welsh landscape.
  • Jess Hey (MBiol): Diet and foraging ecology of storm petrels in the Faeroe Islands.


  • Co-organiser with Dr Renata Medeiros of the annual "Storm Petrels in Portugal" expedition, at A Rocha Bird Observatory, Portugal. This long-running research project investigates the impacts of climate change on marine ecosystems, using the smallest Atlantic seabird, the European Storm Petrel as a sensitive bio-indicator of environmental change [ ]. A video explaining the project is available here:
  • Contributor to BBC Radio 4 programmes (e.g. Nature, Material World, Planet Earth Under Threat) and many Radio Wales programmes.