John Day Building 2.18
Amanda completed her Master’s degree at the University of Cape Town in 2008, focusing on land use and agriculture. Following the completion of her studies, Amanda worked as a farmer and gardener in the United Kingdom for two years, and briefly as a researcher back at the University of Cape Town on her return to South Africa, before she joined the team at Conservation South Africa, an NGO focused on ecosystem health and ecosystem services. At Conservation South Africa, Amanda worked on climate change adaptation and mitigation projects that included ecological restoration, carbon sequestration, community development, and habitat protection and expansion. A large part of her work over the last 6 years has involved testing drylands restoration and improved livestock management as a climate change adaptation in northern Namaqualand.
Amanda is particularly interested in identifying the tipping points and critical thresholds in hot, dry environments that force fundamental trade-offs between necessary fitness and population persistence functions and behaviours, and mitigation of climatic and environmental risk and stress. Arid zone species are unique and interesting as they are typically well-adapted to drought, heat stress, and other climatic extremes, and may therefore be more resilient to the impacts of global warming than other species. Nonetheless, there are considerable lethal and non-lethal physical costs of thermoregulatory behaviour and physiological adaptations, such as reduced forage effort or foraging efficiency on hot days, with the potential to cause significant cumulative declines in condition and productivity over time.
In her PhD, Amanda is exploring the relationship between social behaviour and vulnerability to climate change, with a focus on the impacts of extreme heat on fitness and population persistence in animals in arid environments. Southern Pied Babbler (Turdoides bicolor) will be used as a model species, and fieldwork will be undertaken with the free-ranging, habituated population in the Kuruman River Reserve. The proposed study will test the hypothesis that cooperation, and cooperation in larger groups, will reduce the physiological costs of heat stress and the time spent on thermoregulation. Behavioural observations alongside physiological treatments will be used to assess within-year impacts of heat stress and long term data will be used to identify patterns and critical thresholds.
Can social behaviour, particularly load-sharing, buffer against fitness costs associated with heat stress? Supervisors: Susan Cunningham, Amanda Ridley, and Claire Spottiswoode. Also collaborating with Andrew McKechnie.
Bourne AR, Cunningham SJ, Spottiswoode C, Ridley AR. 2020. Hot droughts compromise interannual survival across all group sizes in a cooperatively breeding bird. Ecology Letters, doi: 10.1111/ele.13604
Bourne, A.R, Cunningham, S.J., Spottiswoode, C., Ridley, A.R. 2020. Compensatory breeding in years following drought in a desert-dwelling cooperative breeder. Frontiers in Ecology and Evolution 8: 190 https://www.
Bourne, A.R, Cunningham, S.J., Spottiswoode, C., Ridley, A.R. 2020. High temperatures drive offspring mortality in a cooperatively breeding bird. Proceedings of the Royal Society B 287 (1931): 20201140 https://
Bourne, A.R., McKechnie, A.E., Cunningham, S.J., Ridley, A.R., Woodborne, S.M. and Karasov, W.H. 2019. Non‐invasive measurement of metabolic rates in wild, free‐living birds using doubly labelled water. Functional Ecology, 33(1): 162-174. https://doi.org/10.1111/1365-2435.13230
Jepsen, E.M., Ganswindt, A., Ngcamphalala, C.A., Bourne, A.R., Ridley, A.R. and McKechnie, A.E. 2019. Non-invasive monitoring of physiological stress in an Afrotropical arid-zone passerine bird, the southern pied babbler. General and Comparative Endocrinology https://doi.org/10.1016/j.ygcen.2019.03.002
Muller, H, and Bourne, A. 2018. Minimum population size and potential impact of feral and semi-feral donkeys and horses in an arid rangeland. African Zoology 53(4): 139-144
Bourne, A., Muller, H., de Villiers, A., Alam, M. and Hole, D. 2017. Assessing the efficiency and effectiveness of rangeland restoration in Namaqualand, South Africa. Plant Ecology 218(7):7-22
Bourne, A,, Holness, S., Holden, P., Scorgie, S., Donatti, C. and Midgley, G. 2016. A socio-ecological approach for identifying and contextualising spatial ecosystem-based adaptation priorities at the sub-national level. PloS One 11(5), e0155235
Carrick, P., Erickson, T., Becker, C., Mayence, E. and Bourne, A.. 2015. A travelling workshop to compare ecological restoration in South Africa and Western Australia. Ecological Management and Restoration 16(2): 86-94.
Bourne, A. 2007. Another World is Possible?: A critical exploration of Escobar’s “other worlds/worlds otherwise”. Anthropology Southern Africa 3(1): 36-44.