Spring Graduation at UKZN is twice the celebration for the Shivambu family as husband and wife team Drs Tinyiko Cavin Shivambu and Ndivhuwo Shivambu receive their PhDs in Zoology.
Both were supervised by South African Research Chair in Ecosystem Health and Biodiversity in KwaZulu-Natal and the Eastern Cape, Professor Colleen Downs. Cavin’s research concerned the highly invasive rose-ringed parakeets in the eThekwini metropolitan area and how they could be managed, while Ndivhuwo looked into the invasion risks posed by the pet trade in non-native mammals and what could be done to mitigate these, with Dr Sandi Willows-Munro co-supervising her work.
They are both from Limpopo Province, where Ndivhuwo attended Maligana Wilson Secondary School and Cavin attended Ramauba Secondary School. The couple met while studying botany and zoology at the University of Venda (UNIVEN), where they went on to complete their Honours in Zoology.
Both received funding from the Department of Science and Innovation – National Research Foundation Centre for Invasion Biology (CIB) to pursue master’s studies in Zoology at the University of Pretoria.
‘Postgraduate life came with its challenges, but we enjoyed the experience, and studying science in particular,’ they said.
After meeting Downs at a CIB general meeting and drawn to UKZN by its ranking amongst the top institutions in terms of its science, teaching and innovation, they decided to enrol for PhD studies in Downs’ lab where they were keen to focus on biological invasions.
‘Biological invasions occur when introduced species colonise new geographic regions, reproduce rapidly, establish, and cause either environmental or socio-economic impacts which can be reversible or irreversible,’ explained the Shivambus.
Cavin said that the rose-ringed parakeet has established feral populations by way of pet trade escapees and intentional releases in South Africa. He used a combination of applied ecology and socio-ecological management to propose appropriate and relevant management solutions.
‘I found that the population of this species is increasing in eThekwini municipality and it competes with native bird species for food and nests,’ he said.
‘Since parakeets are sought after as charismatic invasive species and are kept as pets, my study recommends the introduction of environmental education and engagement with community members so that informed decisions can be made to control them without causing conflict,’ added Cavin.
Ndivhuwo’s research assessed the potential impacts of non-native small mammals in the South African pet trade. Her study found that the widespread trade in exotic small mammals includes many pets regarded as invasive species that could threaten important agricultural crops, biodiversity, and human well-being through disease transmission, and cause infrastructural damage. Furthermore, about 46% of the species are listed under the Convention on International Trade in Endangered Species, including most of the primate species that are sold at higher prices.
‘Given the potential impacts associated with the pet trade, the study recommended that the public, the pet industry, researchers and policy developers should engage in discussions on the development of policies and regulations, and appropriate decision-making and management strategies to prevent future invasions and the decline of native species through the pet trade,’ she said.
During their PhD journey, Ndivhuwo and Cavin authored and co-authored three book chapters and 12 papers, of which three each came from their PhDs. Both are aiming for careers in academia or at research institutions, and they are investigating opportunities for postdoctoral research.
They thanked their families for their support and dedicated their PhDs to their mothers, who encouraged them to study further.
Words: Christine Cuénod