Amphibian populations are declining globally due to interacting pressures from habitat fragmentation, agriculture, road networks and climate change. These stressors operate across spatial and temporal scales, and their combined effects on survival, movement, recruitment and long-term population dynamics remain poorly understood. Despite extensive monitoring, there are few tools capable of predicting amphibian population responses under future scenarios.
This PhD project will develop a process-based, spatially explicit agent-based model for one or more widespread European amphibian species (e.g. Bufo bufo, Rana temporaria, Epidalea calamita), capable of capturing how individuals make movement and life-history decisions in dynamic agricultural landscapes. A baseline model and dynamic energy budget framework already exist, but require development to incorporate individual decision-making, trade-offs among energy, risk and habitat quality, and demographic feedbacks across heterogeneous landscapes.
The model will simulate how amphibians navigate trade-offs between foraging, shelter, moisture, predation, plant protection product exposure and road-crossing risk. Agricultural management, including planting regimes, field margins, soil moisture dynamics, and chronic exposure to plant-protection products, will be integrated with climate-driven changes in hydroperiod, temperature and breeding phenology. Together, these components will allow the exploration of non-linear responses and mitigation scenarios across realistic European agricultural landscapes (illustrative example shown in Figure 1). There is also an opportunity to collect original movement and behavioural data from experimental field or semi-field trials in collaboration with project partners across the UK and Germany where knowledge gaps persist. These trials will provide rare empirical information to refine and parameterise mechanistic movement rules.
Figure 1. Example conceptual overview of a process-based population model for the common toad (Bufo bufo). The model integrates individual movement, habitat structure, stage-structured demography and density dependence, road-crossing mortality, and climate–hydrology drivers to predict population trajectories and evaluate mitigation scenarios.
This PhD will equip you with a highly sought-after interdisciplinary skillset bridging ecological theory, modelling, field ecology, agricultural systems and applied environmental science. As a CASE-supported project with BASF, you will gain insight into ecological risk assessment, landscape-scale modelling and regulatory contexts. Cranfield University offers an advanced modelling environment, high-performance computing, and flexible working arrangements ideal for computational and field-integrated PhD research.
Methodology
You will develop a process-based, spatially explicit population model for European amphibians using an individual-based framework in R and NetLogo with GIS integration. Individuals will make state- and context-dependent decisions, trading off energy gain, moisture balance, shelter, exposure to plant protection products and road-crossing risk. Movement rules will emerge from empirical or experimentally derived relationships between condition, habitat suitability, barrier effects and breeding phenology. Density dependence will link local crowding and resource limitation to egg viability, larval growth, juvenile recruitment and adult condition. Agricultural stressors will capture both chronic and acute effects of management practices and plant protection product exposure. Road mortality will be modelled from road structures and traffic intensity, while climate drivers will incorporate temperature, rainfall, sunshine and hydroperiod. Calibration will use partner datasets and new movement ecology observations collected from field trials. Scenario modelling will evaluate interventions including habitat networks, field-margin design and mitigation structures.
Partners and collaboration
BASF will support the studentship as the CASE partner, offering access to environmental datasets, industrial mentoring, experimental field platforms and opportunities for research placements. Their involvement enables the integration of agricultural management and plant protection product stressors into mechanistic population models. Partners will contribute amphibian ecology expertise, (semi-)field-method support and links with amphibian networks across the UK and Europe. Cranfield University will host the project within its Ecology group, offering modelling expertise, high-performance computing and a flexible, postgraduate-focused research environment ideal for computational-experimental PhD work.
Training and Skills
You will gain advanced training in ecological modelling, movement ecology, landscape ecology, GIS, R and Netlogo programming and population viability analysis. They will develop skills in handling large ecological datasets, integrating landscape and climate data, conducting field or semi-field movement studies, modelling agricultural and pesticide stressors and designing mitigation scenarios. Professional development includes scientific writing, publishing, open science practice, communication with conservation practitioners, public engagement and presenting at conferences. The CASE partnership provides engagement with industry, data-driven environmental decision-making and applied modelling experience directly relevant to careers in academia, consultancy, regulatory science, conservation NGOs and environmental R&D.
Indicative Timeline
Year 1 - Literature review; data collation; individual-based modelling training (R and Netlogo), GIS and movement ecology; initial model framework and simple movement rules.
Year 2 - Original (semi-) fieldwork on amphibian movement ecology (potentially conducted in year 3). Incorporate mechanistic movement rules, density dependence, road mortality and climate drivers in the model; model calibration and validation; first manuscript preparation.
Year 3 - Full scenario simulations (habitat change, climate futures, road mitigation options); evaluation of mitigation scenarios; second manuscript.
Year 4 - Synthesis, uncertainty analysis, stakeholder engagement; final manuscripts; thesis writing and submission.
Entry requirements
The project is open to all applicants who meet the academic requirements (at least a 2:1 at UK BSc level or at least a pass at UK MSc level or equivalent).
Funding
Fully funded NERC CENTA PhD Studentship for 3.5 years with CASE support from BASF. Successful home-fees-eligible candidates will receive an annual stipend of £20,780 per year (pro rata part-time), plus full university fees and a research training support grant.
Please note the grant covers fee costs for a Home award. Unless you are eligible for such a Home award, you will need to consider how you will be able to meet any shortfall in funding for tuition fees, e.g. self-funded. Please contact the supervisors listed on the project for more information.
Diversity and Inclusion at Cranfield
We are committed to fostering equity, diversity, and inclusion in our CDT program, and warmly encourage applications from students of all backgrounds, including those from underrepresented groups. We particularly welcome students with disabilities, neurodiverse individuals, and those who identify with diverse ethnicities, genders, sexual orientations, cultures, and socioeconomic statuses. Cranfield strives to provide an accessible and inclusive environment to enable all doctoral candidates to thrive and achieve their full potential.
At Cranfield, we value our diverse staff and student community and maintain a culture where everyone can work and study together harmoniously with dignity and respect. This is reflected in our University values of ambition, impact, respect and community. We welcome students and staff from all backgrounds from over 100 countries and support our staff and students to realise their full potential, from academic achievement to mental and physical wellbeing.
Cranfield Doctoral Network
Research students at Cranfield benefit from being part of a dynamic, focused and professional study environment and all become valued members of the Cranfield Doctoral Network. This network brings together both research students and staff, providing a platform for our researchers to share ideas and collaborate in a multi-disciplinary environment. It aims to encourage an effective and vibrant research culture, founded upon the diversity of activities and knowledge. A tailored programme of seminars and events, alongside our Doctoral Researchers Core Development programme (transferable skills training), provide those studying a research degree with a wealth of social and networking opportunities.
How to apply
For further information please contact:
Name; Dr Alice Johnston
Email: A.S.Johnston@cranfield.ac.uk
Applicants must complete and upload a CENTA Studentship Application Form 2026 as part of their submission; applications without this form will not be considered
The grant only covers fee costs for a Home award. Unless you are eligible for such a Home award, you will need to meet the shortfall in funding for international tuition fees, e.g. self-fund. Please contact the supervisors.
We have no funds for international students
Students receiving government funding for their degree course are not eligible to apply for a Postgraduate Doctoral Loan.
