Anthropogenic impacts on natural environments such as deforestation, agricultural intensification and the introduction of alien species cause significant changes to the distribution and abundance of species. Species that increase in abundance, whether endemic or introduced, can detrimentally affect other species, including humans.
Across low income countries, rodents contribute significantly to income and food insecurity due to both pre and post-harvest losses. Rodent pests are also reservoirs for rodent-borne infections, a substantial cause of human disease. Effective rodent management strategies, adapted to local circumstances and sustainable for communities, have significant potential to deliver improved well-being and health. However, the development of such strategies is a complex socio-ecological challenge.
In terms of ecology, effective management will depend on how rodent populations respond through compensatory processes such as reproduction and movement. However, the approaches to management taken by individual farmers and communities will depend on the information they have, their perceptions of impacts and the feasibility of management strategies. The ability of some crops, such as rice, to partially compensate for damage incurred early in their growth can result in losses being under-estimated, whilst appreciation of the risk and impact of rodent-borne infections can be low amongst both communities and health professionals. For some individuals and communities, previous experience with ineffective control can lead to defeatism and acceptance of rodent pests, whereas for others cost, perceived effectiveness and a lack of awareness of alternatives can lead to sub-optimal choices regarding control.
Ecological Based Rodent Management (EBRM) techniques exploit relationships between population dynamics and crop production, targeting control in specific locations and seasons. In several Asian agroecosystems EBRM approaches proved effective at reducing crop damage when communities work collectively, and more sustainable than reliance on expensive rodenticides. Application of EBRM in Africa is in its infancy and requires adaptation to local ecological, socio-cultural and economic contexts.
This interdisciplinary project will work with existing projects in Tanzania and Madagascar to explore how to combine understanding of population ecology processes with economic analyses to improve rodent management strategies.
The project will address questions such as:
- what are the perceived and real costs of rodent impacts on crop income, food security and health?
- how does the impact of rodents depend on local and landscape-scale measures of rodent abundance?
- How do individual farmers balance different considerations when taking rodent management decisions (economic, health)?
- What are the main physical and behavioural barriers to the adoption of appropriate rodent management control practices?
- do approaches to risk and uncertainty differ across communities and how does this influence/constrain community-level actions?
- how does the cost-efficiency of different management options compare and how does this depend on ecological and economic factors?
Our ongoing projects are working with 24 communities to conduct and evaluate community-led control trials. In Madagascar, the principal rodent pest is the introduced Rattus rattus, whilst in Tanzania the main rodent pest is an endemic species, Mastomys natalensis. The student will work with research teams in the field to quantify rodent abundance and the rodent damage to crops, stored food and personal possessions and assess the costs (direct and indirect) of alternative management strategies. The student will also explore the economic impact of rodent-borne diseases and use experimental economics to investigate attitudes towards risk, uncertainty and community-action. The student will then investigate how these ecological and economic considerations influence the cost-efficiency of different rodent management options. This could include using simulation modelling to investigate how the efficiency of different management options depends on ecological contexts (e.g. rodent distribution in the landscape) and the costs-benefits of management in specific locations. The relative importance of the different project components will depend on the interests of the student.
The project will suit a student with a background in economics, ecology or development studies and numerical skills, and a strong interest in natural resource management under global change. Competence in French would be an asset. The student will have the opportunity to contribute to the development and implementation of field-work in Africa. The student will be given a thorough multidisciplinary training, including training in the collection of ecological and economic data through a range of methods; statistical analyses; simulation modelling; scientific communication and stakeholder engagement.
The student will interact with experts from a range of fields (pest management, population modelling, environmental economics, anthropology, epidemiology, agriculture) and partner institutes (University of Greenwich, Institut Pasteur de Madagascar, Sokoine University Of Agriculture), as well as local stakeholders.
Funding and eligibility information available here.
|Profile: Sandra Telfer|
Institution: University of Aberdeen
Department/School: School of Biological Sciences
|Profile: Martina Bozzola|
Institution: Queen's University, Belfast
Department/School: School of Biological Sciences
|Profile: Xavier Lambin|
Institution: University of Aberdeen
Department/School: School of Biological Sciences
Constant, N.L., Swanepoel, L.H., Williams, S.T., Soarimalala, V., Goodman, S.M., Massawe, A.T., Mulungu, L.S., Makundi, R.H., Mdangi, M.E., Taylor, P.J., et al. (2020). Comparative assessment on rodent impacts and cultural perceptions of ecologically based rodent management in 3 Afro-Malagasy farming regions. Integr. Zool. DOI: 10.1111/1749-4877.12447
Grant R. Singleton, Steve R. Belmain, Peter R. Brown, and Bill Hardy, editors. 2010. Rodent outbreaks: ecology and impacts. International Rice Research Institute. 289 p. Retrieved from http://books.irri.org/9789712202575_content.pdf
Epanchin-niell, R.S. (2017). Economics of invasive species policy and management. Biol. Invasions 19, 3333-3354. https://doi.org/10.1007/s10530-017-1406-4.
Established approaches for quantifying (i) rodent abundance, (ii) damage to crops at key stages of development and final cumulative damage and (iii) damage to stored food.
Surveys and other approaches (e.g. diaries) to document agricultural activities, household income, time and financial inputs associated with rodent control, health and well-being. These will be enriched with methods from behavioural economics (e.g. economic experiments) to enrich the data with behavioural information.
Use data on incidence and exposure to rodent borne infections in different socio-economic groups (e.g. by age and gender) to explore the economic impact of rodent-borne infections using the concept of Disability-Adjusted Life-Years.
Simulation modelling to explore how a range of factors interact to influence optimal management strategies. These factors may include: the relationships between rodent abundance and impact; the effectiveness of different management strategies in heterogeneous landscapes; the economic costs of rodent damage and the management costs required to achieve a specified reduction in abundance.
Expected Training Provision
Ecological field training: direct and indirect assessment of animal abundance
Statistical analyses of ecological data: robust estimation of rodent abundance (capture data as well as indirect tracking indexes); exploration of environmental factors linked to rodent abundance (crop-type, crop development stage, village and landscape level factors) and determining the nature of the density-dependent relationship between rodent abundance and rodent damage. Likely approaches include program MARK, generalised linear mixed models.
Design and implementation of surveys and experiments to study economic questions.
Statistical analyses of survey data: summarising patterns in responses related to rodent exposure, rodent damage, approaches to rodent control and exploring relationships between patterns and socio-economic and environmental variables (e.g. age, gender, socio-economic status, spatial location of household in village). Multivariate statistics.
Rodents annually destroy cereals that could feed at least 280 million people and rodent-borne infections are a substantial cause of human disease. Leptospirosis alone is one of the world’s most common but neglected zoonoses with an estimated 1 million cases and 60,000 fatalities each year. Developing effective rodent management strategies applicable to low and middle income settings has therefore significant potential to improve health and well-being.
Despite progress in ecologically based rodent management techniques (EBRM), especially in the agricultural sector in Asia, EBRM approaches are poorly developed in Africa. Working in Madagascar and Tanzania, this studentship will address key questions including assessing the perceived and real costs of rodent damage to crops, and how damage varies with rodent abundance; as well as how a range of factors influence rodent management decisions at individual and community levels.
In terms of scientific publications, it is anticipated this project will produce three to four articles. Possibilities include: (i) Inter-country / inter-species comparison of the relationship between rodent abundance and damage; (ii) Factors influencing rodent control decisions at individual and community levels; (iii) How do environmental and economic factors influence the cost-efficiency of different rodent management strategies?; (iv) Holistic assessment of the impact of rodents on the health and well-being.
This project will work alongside ongoing projects (funded by Wellcome and GCRF) with close connections to local institutes, government and other organisations involved in development, pest management and public health. It is hoped that the student would be directly involved in presenting their research to stakeholder meetings, and generating research summaries to support policy decisions.
Ultimately the outcomes will be relevant to rural communities throughout most low- and middle-income countries facing problems with high numbers of rodent pests and disease.
Sandra Telfer is a Senior Research Wellcome Trust Fellow at the University of Aberdeen, with research focussing on population ecology, disease ecology, the epidemiology of zoonoses (especially rodent-borne zoonoses) and strategies to mitigate zoonotic risk. Her research includes studies in Scotland, Tanzania and Madagascar. ST will provide training in field techniques for population ecology, advanced statistical analyses of ecological data (abundance estimates, generalised linear mixed models).
Martina Bozzola is a Lecturer in the economics of agriculture, food and health, at the School of Biological Sciences, Queen’s University Belfast. Dr Bozzola’s main research and teaching focus is on: agricultural and development economics (decision making under risk, technology adoption, food and nutrition security), climate change economics and sustainable value chains and environmental management. MB has extensive experience in both research and field work in West, East and Southern Africa, and has a current project funded by the Royal Academy of Engineering, with a focus on enhancing food and nutrition security in Madagascar. MB will provide training in survey design and implementation, economics and stakeholders engagement.
Xavier Lambin is a Professor in ecology at the University of Aberdeen. He is an expert in the population ecology and management of invasive species, with substantial experience in interdisciplinary projects and research across the globe, including the UK and South America. XL will provide additional support in the analysis and interpretation of data, and engagement with stakeholders and policy makers.
The GCRF project will start work in 2021, collecting initial data, before expanding to additional sites in 2022. Thus, the student will have access to data from the beginning of their project, ensuring they can conduct analyses and start an initial publication, whilst also developing their ideas and planning future work.
Year 1 (2021-2022)
Months 1-4: Literature review, initial exploration of existing data from rodent and household surveys to facilitate project development.
Months 4-6: Initial training in methodologies and stakeholder engagement, and development of project plan for field work. This may include further quantification of rodent damage, and using behavioural economic approaches to evaluate attitudes to risk and uncertainty.
Months 7-12: Fieldwork in Madagascar and/or Tanzania as appropriate. Mitigation plan in case COVID-19 pandemic does not allow for fieldwork: work in close collaboration with the local teams and established networks of the supervisory team to coordinate and lead remotely the data collection process.
Months 13-15: Further analysis of abundance and damage data and drafting of article on quantifying the relationship between abundance and damage in different contexts.
Months 16-18: Evaluation of data from studies on attitudes to risk, uncertainty.
Months 17-18: Planning of additional fieldwork
Months 19 – 24: Further fieldwork if required (coinciding with end of community-led control initiatives on GCRF project – options could include looking at changes to perceptions of rodent impact or attitudes towards control).
Month 25-27: Further analysis of data on perceptions/attitudes and drafting of article on factors influencing control decisions
Months 28-33: Further analyses / modelling. Several options depending on interest of student – e.g. combined impacts of rodent pests on health and well-being; landscape-scale modelling to explore cost-efficiencies of different management strategies.
Month 34-36: Finalise manuscripts
Year 4 (6months)
Month 36 onwards: Thesis write up and additional papers
Non-CASE collaborators: University of Greenwich, Institut Pasteur de Madagascar, Sokoine University Of Agriculture, and local stakeholders.