Hot Birds Research Project
Principal Investigators
The Hot Birds Research Project is a partnership between the FitzPatrick Institute of African Ornithology at the University of Cape Town, and the University of Pretoria, with collaborators at other universities, NGOs and research organisations internationally. It is co-led by Prof. Susan Cunningham at the University of Cape Town and Prof. Andrew McKechnie at the University of Pretoria and South African National Biodiversity Institute, in a productive research partnership spanning over a decade. Find out more about our two PIs below.
Prof. Andrew McKechnie
Contact
Prof. Andrew E. McKechnie
Department of Zoology and Entomology
University of Pretoria
Pretoria, 0002
South Africa
South African Research Chair in Conservation Physiology
South African National Biodiversity Institute
Email: andrew.mckechnie@up.ac.za
Tel: +27 12 420 3232
Andrew McKechnie is a Professor in the Department of Zoology and Entomology at the University of Pretoria, and the South African Research Chair of Conservation Physiology at the South African National Biodiversity Institute. He obtained his Ph.D. from the University of Natal in 2002, where his postgraduate research focused on the ecology and evolution of avian heterothermy. Thereafter, he spent two years as a postdoctoral fellow at the University of New Mexico before returning to South Africa in 2004 to take up a position at the University of the Witwatersrand, where he remained until moving to the University of Pretoria in early 2008. He was acting Deputy Dean: Research and Postgraduate Studies in the Faculty of Natural and Agricultural Sciences during the period August 2014 to March 2015. He has been a core team member of the DST-NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology at the University of Cape Town since the Centre was established in 2004. He is currently Associate Editor for two journals, namely Global Change Biology and Emu – Austral Ornithology, and is a member of the editorial board of Journal of Comparative Physiology B.
Research interests
My research interests fall into three major areas:
Physiological approaches to predicting climate change impacts on arid-zone birds
Empirical data on the temperature dependence of a suite of physiological and behavioural variables are needed to parameterise models linking current and future climates to survival and reproduction over time scales ranging from hours to seasons. One key aspect of this work involves quantifying variation among and within species in heat tolerance limits and evaporative cooling capacities; this information is vital for understanding whether birds will be able to cope with more frequent and intense heat waves.
Avian physiological diversity: integrating sources of phenotypic variation
This component of my research program seeks to understand how different sources of phenotypic variation in physiological traits interact with each other and contribute to physiological diversity. My work in this area has focused primarily on metabolic rates, and to a lesser extent evaporative water loss rates. My approach involves a combination of experimental work under laboratory conditions, investigation of physiological variation in free-ranging populations, and synthetic analyses of published data.
Ecology and evolution of heterothermy
My work on heterothermic responses in birds relies on three complementary approaches: quantifying heterothermy under natural conditions in order to better understand the phylogenetic distribution and ecological determinants of heterothermic responses, experimental manipulations of energy balance to elucidate proximate determinants of heterothermic responses, and bioenergetic modeling and literature reviews.
Key Publications (complete list here)
Freeman, M.T., Coulson, B., Short, J.C., Ngcamphalala, C.A., Makola, M.O. and McKechnie, A.E. 2024. Evolution of avian heat tolerance: the role of atmospheric humidity. Ecology 105: e4279
Conradie, S.R., Kearney, M.R., Wolf, B.O., Cunningham, S.J., Freeman, M.T., Kemp, R. and McKechnie, A.E. 2023. An evaluation of a biophysical model for predicting avian thermoregulation in the heat. Journal of Experimental Biology 226: jeb245066.
​
McKechnie, A.E., Freeman, M.T. and Brigham, R.M. 2023. Avian heterothermy: a review of patterns and processes. Integrative and Comparative Biology icad029.
​
Freeman, M.T., Czenze, Z.J, Schoeman, K. and McKechnie A.E. 2022. Adaptive variation in the upper limits of avian body temperature. Proceedings of the National Academy of Sciences, U.S.A. 119(26): e2116645119.
​
​
McKechnie, A.E. and Wolf, B.O. (2010). Climate change increases the likelihood of catastrophic avian mortality events during extreme heat waves. Biology Letters 6: 253-256.
Professor Susan Cunningham
Contact
Associate Professor Susan J. Cunningham
FitzPatrick Institute of African Ornithology
Department of Biological Sciences
University of Cape Town
Rondebosch, 7701
South Africa
Email: susan.cunningham@uct.ac.za
Tel: + 27 21 650 33 06
Susie is an associate professor and the Director of the FitzPatrick Institute at the University of Cape Town. She is PI of the behaviour side of the programme. She works on projects integrating behavioural and physiological approaches to understand the thermal biology of birds.
Susie is a New Zealander and completed her undergraduate degrees in Ecology & Biodiversity and Classical Studies at Victoria University of Wellington, and her Ph.D. on tactile sensory systems in birds at Massey University. She moved to South Africa in 2010 and spent her first field season in the Kalahari over the summer of 2010/11 - South Africa is now her second home.
The focus of Susie’s and her students’ field work is on the relationship between thermal biology and behavioural ecology, in particular the fitness consequences of behavioural thermoregulation; and how changes in behaviour can influence species interactions and ecosystem function.
Research interests
Opportunity costs and fitness consequences associated with behavioural thermoregulation
Animals routinely modify their behavior to buffer physiological impacts of high temperatures (e.g. ceasing activity, seeking shade), but opportunity costs associated with these behavioral changes are pervasive. These costs have potential impacts at multiple scales from individual fitness to population persistence to ecosystem function. My students, collaborators and I have worked on understanding these costs and their consequences, since 2012. We published the first empirical data on this theme between 2012 and 2020, building the case for the profound impact of behavioural costs of thermoregulation across multiple taxa. In 2021, we published a synthesis paper in the journal Frontiers in Ecology and the Environment, to highlight that behavioural changes for thermoregulation do not come for free - and that they may also alter interactions between species thereby influencing ecosystem function as the world warms.
​
Climate change vulnerability and the complex interplay between behaviour and physiology
Together with my students and collaborators, I conduct integrative work across the boundaries of behavioural ecology and ecophysiology. To date this work has highlighted that thermoregulation in free-ranging animals involves complex integration of behavioral and physiological responses to changing thermal conditions and cannot be explained by measurements of thermal physiology, or observations of behavior, alone. Current work in this theme aims to understand the combined behavioural and physiological strategies birds use to thermoregulate, why these vary between species occupying the same environments, and what the consequences are for fitness in a changing world.
Global change is not just climate change
Climate change interacts with other global change drivers, for example land use change and urbanisation, to affect species and populations. The interplay between global change drivers can exacerbate or buffer impacts on behaviour and fitness consequences of these. My students, collaborators and I study the relationships between climate change and urbanisation to untangle the consequences of these two drivers acting in concert on behaviour, physiology and fitness of urban birds.
​
Key Publications (complete list here)
​​
Cunningham, S.J. 2024. Climate change. In: Behavioural Responses to a Changing World. Edited by: B. M. Wong and U. Candolin, Oxford University Press. ISBN 9780192858979 [Peer-reviewed book chapter]
​​​
Sumasgutner, P.*, Cunningham, S.J.*, Hegemann, A., Amar, A., Watson, H., Nilsson, J., Andersson, M.N., Isaksson, C. 2023. Interactive effects of rising temperatures and urbanisation on birds across different climate zones: a mechanistic perspective. Global Change Biology. https://doi.org/10.1111/gcb.16645. *joint first authors
​​​​​
Bourne, A.R., Ridley, A.R., McKechnie, A.E., Spottiswoode, C.N. & Cunningham, S.J. 2021. Dehydration risk is associated with reduced nest attendance and hatching success in a cooperatively breeding bird, the southern pied babbler Turdoides bicolor. Conservation Physiology 9. coab043.
​
​Cunningham, S.J., Gardner, J., & Martin, R. O. 2021. Opportunity costs and the response of birds and mammals to climate warming. Frontiers in Ecology and the Environment. 19: 300-307. http://doi.org/10.1002/fee.2324
​​
van de Ven, T.M., McKechnie, A.E. and Cunningham, S.J. (2019). The costs of keeping cool: behavioural trade-offs between foraging and thermoregulation are associated with significant mass losses in an arid-zone bird. Oecologia doi: 10.1007/s00442-019-04486-x
​​