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Landscape Ecologist joins SAEON’s Ndlovu Node
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As a young boy growing up in rural Zimbabwe, George Chirima became fascinated by the wonders of the natural environment in which he was raised.
His quest to know increasingly more about nature turned him into an insatiable learner, and on leaving school it was only natural for him to pursue his studies in environmental science at the University of Zimbabwe.
In those early days all he wanted to do was to qualify as a teacher so that he could impart his knowledge of the natural environment to Zimbabwe’s young learners. With a BSc Honours in Biological Sciences under his belt, he started his teaching career at St John’s High School where he taught biology, physics and chemistry.
He was enlisted by Cambridge University to be an international high school examiner in biology and became actively involved in setting and marking O-level and Advance-level high school exams. He was delighted when he won a bursary to study for a Masters degree in Science Education at the University of Havana.
Although he enjoyed teaching in all its facets, it gradually dawned on him that his real passion lay in doing the actual science, and once he decided to pursue this passion, his life took a dramatically different turn.
Quantitative data analysis
At the University of Zimbabwe, he came into contact with Dr David Cumming and Dr Ngoni Moyo who both had a major influence on his career. George was allowed to become part of their team, which opened doors for him to the exciting world of mammal ecology.
While studying towards an MSc in Tropical Resources Ecology at the University of Zimbabwe, he met two US researchers who were to have a marked influence on his career — Alicia Linzey and Mike Kesner from Indiana University. They were visiting the University of Zimbabwe to give seminars on quantitative data analysis and conduct research in collaboration with the university. George assisted them with data collection and the three of them became good friends.
“I soon came to realise the importance of data collection and analysis as well as the use of models, not only in my field of tropical research management and ecology, but in environmental science in general,” George explains.
Yet at the time, few universities provided training in modelling, quantitative methods and data analysis to ecologists in Southern Africa. George resolved to find out more about this new field that was a scarce skill in the region. Shortly after completing his MSc, he received a bursary to study quantitative methods and statistical modelling for Conservation Biology at Indiana University.
Despite an offer to do a PhD in the US, George opted to come back to Africa to work on African mammals. He joined the University of the Witwatersrand in South Africa. Under the mentorship of Prof Norman Owen-Smith and Dr Barend Erasmus, he worked as a Graduate Teaching Assistant in the School for Animal, Plant and Environmental Sciences lecturing on savanna ecology, population and resources as well as savanna diversity and savanna soils.
Habitat suitability assessments of sable antelope
For his PhD he worked on habitat suitability assessments of the sable antelope in the Kruger National Park. George admits that he enjoyed every minute of his research. “I love antelope and I love nature,” he says with a wide grin.
George became involved in the sable antelope project as these magnificent antelope were declining in Kruger Park and nobody knew why it was happening.
With his study leaders Prof Norman Owen-Smith and Dr Barend Erasmus, he designed a project to study this antelope species occurring at the edge of its geographic range in Africa. He explains that sable antelope are in competition with buffalo, zebra, wildebeest and impala for similar resources in Kruger Park and hence the study concentrated on core areas preferred by these animals and in sections of the park where they did not occur in order to identify factors governing their distribution.
They studied other large antelope species in these core areas to see how they were doing in comparison with the sable antelope and looked at the annual Kruger census data to draw comparisons as to whether the other species started disappearing around the same time or whether their numbers remained more or less the same. The researchers suggest that the spatial pattern of how a species disappears from previously occupied areas holds vital clues to the reason why it is disappearing.
The study found several causes for the decline in large antelope, chief among these being predation, mostly by lion. “The research group modelled the distribution of lions and lion abundance and realised that predation did in fact have a major effect on the numbers and in restricting the wider spatial distribution of these antelope,” George explains.
He is currently working on a publication highlighting the effect of climate on changes in antelope distribution and abundance decline.
George’s work in the Kruger Park made him realise that this was where he wanted to live and work. When the position at SAEON’s Ndlovu Node came up he jumped at the chance. He joined SAEON in March this year as a Landscape Ecologist.
“I love the way SAEON is working on big scales — both in space and in time,” George says. He aims to put his experience and expertise in spatial modelling to good use in monitoring long-term environmental trends.
Of rainfall, elephants and goats
George is currently involved with three projects at SAEON Ndlovu, the first of which involves evaluating whether the relationship between rainfall and the Normalised Difference Vegetation Index1 (NDVI) in savannas is changing with climate change. As a Landscape Ecologist George is fascinated by changes at the landscape scale. He explains that these could result from various factors including regime shifts due to climate change or just natural variation due to different geology, and ways need to be found to unpack and distinguish natural variation from effects associated with climate change.
To predict climate change in savannas, researchers normally use the the relationship between the NDVI and precipitation. In view of climate change, however, if rainfall becomes erratic, the question arises whether this relationship between the NDVI and precipitation should still be used to predict climate change.
The second project involves looking at long-term impacts of the Kruger Park’s elephant population. “Whenever elephant impacts are discussed, for example whether elephants should or shouldn’t be culled, conservation managers always indicate that they need more data,” George says.
Actual studies that have looked at the impact of elephants on the landscape are insufficient to enable conservation managers to formulate policies to manage elephants. Long-term monitoring research work is still necessary to assess the impact of the elephants reliably. For this purpose, the Kruger Park has set up elephant exclosures, a situation that is ideal for manipulative experiments.
The third project stems from his mission to work with rural people to achieve sustainable land practices. It is a project that he is currently developing with other Ndlovu Node scientists and Joe Sibiya, the Node’s Education Outreach Officer. It revolves around resource selection by goats in the rural villages adjacent to the Kruger Park. George explains that goats are a good source of protein and cheaper than beef and mutton in SA, so they will be looking at identifying the types of resources used by goats around local schools.
With his background in both science and education, George says he is looking forward to mentoring the young learners involved in the project.
“As my own mentors, Prof Norman Owen-Smith and Dr Barend Erasmus indicated, the work at SAEON fits me like a glove – it draws together all my passions and I hope to be able to make a lasting contribution not only to environmental research, but, remembering the curious youngster I once was, also to the lives of the rural learners I will be mentoring,” he says.
1 The Normalized Difference Vegetation Index (NDVI) has been in use for many years to measure and monitor plant growth (vigor), vegetation cover, and biomass production from multispectral satellite data.
