Browse/search for people

Professor Michael Mendl

Professor Michael Mendl

Professor Michael Mendl
MA, PhD(Cantab), BA (Hons)

Professor of Animal Behaviour and Welfare

Area of research

Animal Welfare, Emotion and Cognition

Division of Animal Health and,
Husbandry, Langford House BS40 5DU
(See a map)

+44 (0) 117 928 9485



PhD opportunity: Biases in decision-making and their implications for resilience and animal welfare

There is growing interest in understanding why some individuals are more resilient to challenge than others. A key predictor of resilience in humans is the way in which people appraise or judge a situation, as this determines the decisions they make and hence the impact that the situation has on them. The aims of this PhD are to carry out the first in-depth investigation of the links between decision-makig style and resilience in an animal species (rats).

Deadline: 5 Dec 2016. For information on how to apply, go to: 

For more detail on the project, go to:


My research

My research interests are in the area of animal behaviour and welfare.

I am interested in the links between affective and cognitive processes, in particular the ways in which attention, memory and decision-making both influence and are influenced by affective state. One aim of our current research, in collaboration with psychologist Dr Liz Paul, is to investigate whether affect-induced modulation of decision-making, which leads to so-called 'cognitive bias' in humans, is also observed in animals, and hence can be used as a novel indicator of animal affect (emotion) and welfare.

I am also interested in the evolution and function of affective states, developing new measures of animal emotion and welfare that can be used under field conditions, and understanding more about animal cognition, emotion, personality, and social behaviour with a view to identifying and minimising welfare problems for captive animals.

I also have interests in the influence of early experience and social behaviour (including mother-offspring relations, early husbandry procedures, and 'abnormal behaviours' such as tail-biting in pigs) on behavioural development, an individual's ability to cope with challenge, and animal welfare.


Michael Mendls' Research

Research areas

  • Cognition and emotion in animals (‘cognitive bias’)
  • Assessment of animal welfare
  • Animal cognition
  • Individual differences in behaviour and coping style
  • Stress and cognitive function
  • Early experience effects on behavioural development and subsequent coping ability / vulnerability to welfare problems
  • Interactions between stress, immune function, health and welfare
  • Tail-biting in pigs

Current projects

NC3Rs: Development and validation of an aut omated test of animal affect and welfare for laboratory rodents (PI: Mike Mendl; Co-Is: Liz Paul (Vet Science), Peter Dayan (Gatsby Computational Neuroscience Unit, UCL), Emma Robinson (Physiology & Pharmacology); Postdoc: Sam Jones). We are developing an automated cognitive bias task for lab rats and mice.

BBSRC: Validation and differentiation of welfare indicators in laying hens (PI: Christine Nicol; Co-Is: Mike Mendl, Bill Browne, Suzanne Held; Named researcher: Liz Paul; Technician: Ilana Kelland). We are investigating how welfare indicators and cognitive bias measures co-vary and reflect long-term cumulative experience of positive and negative events.

BBSRC: Defining a pain phenotype that is predictive of altered central pain processing in dogs with spontaneous osteoarthritis (PI: Jo Murrell; Co-Is: Mike Mendl, Toby Knowles, Becky Whay, Sara Kelly (Nottingham), John Harris (Nottingham); Postdoc: James Hunt; Technician: Helen Jenkins). We are developing methods to measure the pain that dogs affected by osteoarthritis may be experiencing, and how ands why this may differ between individuals.

Current research fellows

  • Carole Fureix – Marie Curie Fellow – Memory bias as a novel indicator of animal affect and welfare

Current PhD students

  • Amanda Deakin (Supervisors: Mike Mendl, James Hodge (Physiology & Pharmacology), Bill Browne (Centre for Multilevel Modelling)) - Decision-making in Drosophila melanogaster
  • Emma Mellor (Supervisors: Mike Mendl, Innes Cuthill (Biological Sciences), Georgia Mason (University of Guelph)) - Using the comparative approach to identify species' risk factors for abnormal behaviour and poor welfare in captivity
  • Vikki Neville (Supervisors: Mike Mendl, Liz Paul, Iain Gilchrist (Psychology), Peter Dayan (UCL)) - Emotion and decision-making: disentangling underlying processes 
  • Justyna Papciak (Supervisors: Emma Robinson (Physiology & Pharmacology), Mike Mendl) – Novel approaches to the assessment of affective state in rodents
  • Rogelio Rodriguez (Supervisors: Mike Mendl, Suzanne Held, Sue Dow (Bristol Zoo)) – Clever keas: cognition and cognitive enrichment
  • Anne Seawright (Supervisors: Mike Mendl, Rachel Casey, Emily Blackwell) - Cognitive bias and welfare in kennelled domestic dogs
  • Melissa Smith (Supervisors: Jo Murrell, Mike Mendl) – Understanding pain perception in dogs with osteoarthritis
  • Timothy Tan (Supervisors: Kath Handasyde (Univ Melbourne, Australia), Mike Mendl) - Cognitive bias in lizards and fish

Current MSc by research students

Previous lab members

Research findings

  • Development of a new technique for measuring biases in decision-making under ambiguity ('judgement biases') in non-human animals
  • Affect-induced judgement biases appear to be reliable new indicators of animal emotion and welfare
  • Affect-induced judgement biases have now been observed in rats, humans and dogs. Other labs have used our technique to demonstrate them in rodents, sheep, starlings, rhesus monkeys, pigs, and honeybees
  • Sensitivity to reward loss may also be a useful new indicator of animal emotion and welfare
  • 'Discrete' and 'dimensional' theories of emotion can be integrated to provide a functional view of animal emotion and the role of affect in altering decision-making
  • The influence of threat (e.g. probability of predation) on optimal decision-making by combined fast/inaccurate and slow/accurate mechanisms can be modelled
  • Early experience of stressful husbandry effects may have lifelong consequences in sheep
  • Pigs can adjust their foraging behaviour to avoid their knowledge being exploited depending on whom they are foraging with

If you are interested in joining our research group, contact me at:

Further information about Professor Michael Mendl can be found here


I graduated in 1982 with a degree in Natural Sciences from Cambridge University and then stayed on to study for a PhD on mother-offspring relationships and behavioural development supervised by Prof Pat Bateson FRS at the Cambridge Zoology Department's Sub-Department of Animal Behaviour. I completed my PhD in 1986 and was then awarded a Royal Society European Research Fellowship to continue work on behavioural development and individual differences in house mice at Groningen University in the Netherlands. I then returned to Cambridge University and took a postdoc position at the Vet School where I moved into the fields of applied behaviour and animal welfare and was introduced to the intelligence, grace and equipment destroying capabilities of the domestic pig. In 1993, I took up a position as a behavioural scientist at the Scottish Agricultural College in Edinburgh, continuing to work on pig behaviour and welfare, and then moved to Bristol University Vet School in 1997 where I am now Professor of Animal Behaviour and Welfare. and have previously been Head of the Bristol Animal Welfare & Behaviour Group, and Deputy Head of School (Research). At Bristol, my research interests have been in the study of cognition, emotion, development, individuality and social behaviour in domestic animals (pigs, dogs, rats, sheep), with a view to using this information to improve animal welfare, and in more applied animal welfare issues including the relationship between housing and husbandry procedures and the health and welfare of farm and laboratory animals, and understanding abnormal behaviour such as tail-biting in pigs.


  • emotion
  • cognition
  • decision-making
  • animal welfare
  • animal behaviour



Farm Animal Science

Other sites

Research areas

Research: Cross cutting research

Research: Animal Welfare and Behaviour

Selected publications

Read more >

Recent publications

View complete publications list in the University of Bristol publications system

Edit this profile If you are Professor Michael Mendl, you can edit this page. Login required.

PDF versionDownload PDF