Fully-funded ARIES PhD project: Modelling butterfly abundance at varying spatial scales to inform conservation delivery

Click here to submit your application by the 8th of January.

If you have any queries please email Rachel McCrea: R.S.McCrea@kent.ac.uk


Dr Rachel McCrea, University of Kent and Dr Emily Dennis, Butterfly Conservation


Other Supervisory Team Members

Professor Byron Morgan, University of Kent

Professor Tom Brereton, Butterfly Conservation

Dr David Roy, Centre for Ecology and Hydrology

Project Summary

Three-quarters of UK butterfly species have declined over the past four decades. Butterflies respond quickly to habitat and climatic change, hence their population status is a valuable biodiversity indicator. Analysis of long-term butterfly monitoring datasets has provided some of the world’s best evidence of the biological impacts of climate change, including major phenological and distribution shifts, evolutionary responses and the impacts of extreme events.

Population trends are primarily assessed at national scales. This project will undertake more detailed analysis across spatial scales (e.g across regions, specific habitats or individual sites) to identify butterfly population responses to major drivers of change.  As well as delivering high impact scientific insight, this will underpin more effective conservation, from local land management to strategic planning across regions, including the production of new biodiversity indicators and site level alerts.

National-scale butterfly monitoring will be enhanced by refining survey guidance for threatened species, improving knowledge of butterfly lifespans and furthering methods for assessing species threatened status.


A key feature of statistical models applied to butterflies1,2 involves accounting for seasonal variation in counts, as butterflies emerge throughout the year via one or more broods. Flight period patterns vary geographically, for example emergence can be later further north in the UK3. Seasonal patterns are typically assumed to be fixed across space. Counts from the UK Butterfly Monitoring Scheme (UKBMS) are made under standardised conditions4 to minimise bias due to variation in the probability of detecting individuals.


Project Aim

To better explain butterfly population dynamics during a period of rapid environmental change, to project future changes under scenarios of climate change and to create direct benefits for the conservation of butterflies.



  1. Determine whether accounting for spatial variation in phenology influences population trend estimates, particularly at varying scales, where data are likely to be sparser and more susceptible to variation.
  2. Assess the influence of external factors such as weather and time of day on counts and population trends. Identify optimal times of day for detecting target species and testing for evidence of lower counts on hot days as butterfly activity may drop in extreme temperatures. Fine-tune UKBMS sampling procedures and guidance.
  3. Extend knowledge of butterfly lifespans. Further verification of recently developed models5,2 via simulation-based testing and comparison with estimates from capture-recapture data. Assess the influence of lifespans on butterfly population trends and determine their relevance for measuring species conservation status e.g. classifying Red Lists6.
  4. Account for lifespan and variation in detection to produce more robust population trend estimates. Trends for under-utilised local scales or habitat types will provide new scientific insights and will allow Butterfly Conservation to better assess and refine conservation and policy measures to inform where to direct management efforts. This has particular relevance for Priority Species for conservation action and for some more common butterfly species for which the drivers of recent population declines are not well understood.


Person Specification and Training Opportunities


Applicants should have a good degree in a subject such as statistics, mathematics, or another scientific discipline with a substantial quantitative component. A keen interest in ecology is advantageous.


The student will benefit from being immersed in an established Statistical Ecology @ Kent (SE@K) research group (and its wider collaborators), with training opportunities through National Centre for Statistical Ecology (NCSE) meetings, Academy for PhD Training in Statistics courses and the ability to contribute to the running of specialist quantitative training events lead by SE@K.  The student will develop practical skills through field-work and data collection with Butterfly Conservation and will attend ARIES DTP training events to develop essential environmental science skills.  The student will have extensive opportunity to present their work to varied communities (wider membership of NCSE, statistical and ecological conferences and organisations currently working with members of SE@K).  By spending part of the project with Butterfly Conservation, the student will gain experience of working within a conservation organisation and gain new skills through attending field surveys and QGIS training. The supervisory team will ensure ample opportunity for independent development.  On graduating, the student will possess a transferable knowledge of modern methods of data science and statistics which will be particularly applicable for careers in conservation and ecology as well as other applied fields.


The project has been shortlisted for up to 4 years, with 3.5 years minimum, of funding by the ARIES NERC Doctoral Training Partnership (https://www.aries-dtp.ac.uk) with a stipend of £14,777 per annum and a generous training and travel budget for attending UK-based and international conferences, as well as for time spent visiting Butterfly Conservation.


ARIES is committed to equality & diversity, and inclusion of students of any and all backgrounds. All ARIES Universities have Athena Swan Bronze status as a minimum.


Students with high level numerical skills will be eligible for 3 months of additional stipend after the end of the 3.5 years to take advanced-level courses in branches of environmental sciences related to the project in the first 3-6 months of study.


Shortlisted applicants will be interviewed on 26th/27th February 2019.


Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship – in 2018/19 the stipend is £14,777. In most cases, UK and EU nationals who have been resident in the UK for 3 years are eligible for a full award.



1Dennis, E.B., Morgan, B.J.T., Freeman, S.N., Brereton, T.M. and Roy, D.B. (2016). A generalized abundance index for seasonal invertebrates. Biometrics, 72, 1305-1314.

2Dennis, E.B., Morgan, B.J.T., Brereton, T., Freeman, S.N. and Roy, D.B. (2016). Dynamic models for longitudinal butterfly data. Journal of Agricultural, Biological, and Environmental Statistics, 21, 1-21.

3Roy, D.B. and Asher, J. (2003). Spatial trends in the sighting dates of British butterflies. International Journal of Biometeorology, 47, 188-192.

4Pollard, E. and Yates, T.J. (1993). Monitoring Butterflies for Ecology and Conservation: the British Butterfly Monitoring Scheme. Chapman & Hall, London.

5Matechou, E., Dennis, E.B., Freeman, S.N. and Brereton, T. (2014). Monitoring abundance and phenology in (multivoltine) butterfly species: a novel mixture model. Journal of Applied Ecology, 51, 766-775.

6Bubová, T., Kulma, M., Vrabec, V. and Nowicki, P. (2016). Adult longevity and its relationship with conservation status in European butterflies. Journal of Insect Conservation, 20, 1021-1032.