Robert Guldemond

Dr. Robert Guldemond


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 June 2017 in PLOS ONE
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Journal Article
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RGRobert Guldemond
Robert Guldemond
APAndrew Purdon
Andrew Purdon
RARudi J Van Aarde
Rudi J Van Aarde
Contradictory findings among scientific studies that address a particular issue may impede the conversion of science to management implementation. A systematic review of peer-reviewed studies to generate a single outcome may overcome this problem. The contentious topic of the impact that a megaherbivore such as the savanna elephant have for other species and their environment can benefit from such an approach. After some 68 years, 367 peer-reviewed papers covered the topic and 51 of these papers provided sufficient data to be included in a meta-analysis. We separated the direct impact that elephants had on trees and herbs from the indirect effects on other vertebrates, invertebrates, and soil properties. Elephants have an impact on tree structure and abundance but no overall negative cascading effects for species that share space with them. Primary productivity explained a small amount of variation of elephant impact on vegetation. Elephant numbers (density), study duration, rainfall, tree cover, and the presence of artificial water and fences failed to describe patterns of impact. We conclude that published information do not support the calls made for artificially manipulating elephant numbers to ameliorate elephant impact, and call for the management of space use by elephants to maintain savanna heterogeneity.

5 January 2024 in Science Advances
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Journal Article
Open access
RHRyan M. Huang
Ryan M. Huang
CMCelesté Maré
Celesté Maré
RGRobert Guldemond
Robert Guldemond
SPStuart Pimm
Stuart Pimm
RARudi J. van Aarde
Rudi J. van Aarde
The influence of protected areas on the growth of African savannah elephant populations is inadequately known. Across southern Africa, elephant numbers grew at 0.16% annually for the past quarter century. Locally, much depends on metapopulation dynamics—the size and connections of individual populations. Population numbers in large, connected, and strictly protected areas typically increased, were less variable from year to year, and suffered less from poaching. Conversely, populations in buffer areas that are less protected but still connected have more variation in growth from year to year. Buffer areas also differed more in their growth rates, likely due to more threats and dispersal opportunities in the face of such dangers. Isolated populations showed consistently high growth due to a lack of emigration. This suggests that “fortress” conservation generally maintains high growth, while anthropogenic-driven source-sink dynamics within connected conservation clusters drive stability in core areas and variability in buffers.

30 March 2025 in Veterinary Sciences
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Journal Article
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MMMargot Morel
Margot Morel
RGRobert Guldemond
Robert Guldemond
MGMelissa Ann de la Garza
Melissa Ann de la Garza
Jaco BakkerJaco Bakker
Jaco Bakker
Elephants exhibit remarkable cognitive and social abilities, which are integral to their navigation, resource acquisition, and responses to environmental challenges such as climate change and human–wildlife conflict. Their capacity to acquire, recall, and utilise spatial information enables them to traverse large, fragmented landscapes, locate essential resources, and mitigate risks. While older elephants, particularly matriarchs, are often regarded as repositories of ecological knowledge, the mechanisms by which younger individuals acquire this information remain uncertain. Existing research suggests that elephants follow established movement patterns, yet direct evidence of intergenerational knowledge transfer is limited. This review synthesises current literature on elephant navigation and decision-making, exploring how their behavioural strategies contribute to resilience amid increasing anthropogenic pressures. Empirical studies indicate that elephants integrate environmental and social cues when selecting routes, accessing water, and avoiding human-dominated areas. However, the extent to which these behaviours arise from individual memory, social learning, or passive exposure to experienced individuals requires further investigation. Additionally, elephants function as ecosystem engineers, shaping landscapes, maintaining biodiversity, and contributing to climate resilience. Recent research highlights that elephants’ ecological functions can indeed contribute to climate resilience, though the mechanisms are complex and context-dependent. In tropical forests, forest elephants (Loxodonta cyclotis) disproportionately disperse large-seeded, high-carbon-density tree species, which contribute significantly to above-ground carbon storage. Forest elephants can improve tropical forest carbon storage by 7%, as these elephants enhance the relative abundance of slow-growing, high-biomass trees through selective browsing and seed dispersal. In savannah ecosystems, elephants facilitate the turnover of woody vegetation and maintain grassland structure, which can increase albedo and promote carbon sequestration in soil through enhanced grass productivity and fire dynamics. However, the ecological benefits of such behaviours depend on population density and landscape context. While bulldozing vegetation may appear destructive, these behaviours often mimic natural disturbance regimes, promoting biodiversity and landscape heterogeneity, key components of climate-resilient ecosystems. Unlike anthropogenic clearing, elephant-led habitat modification is part of a long-evolved ecological process that supports nutrient cycling and seedling recruitment. Therefore, promoting connectivity through wildlife corridors supports not only elephant movement but also ecosystem functions that enhance resilience to climate variability. Future research should prioritise quantifying the net carbon impact of elephant movement and browsing in different biomes to further clarify their role in mitigating climate change. Conservation strategies informed by their movement patterns, such as wildlife corridors, conflict-reducing infrastructure, and habitat restoration, may enhance human–elephant coexistence while preserving their ecological roles. Protecting older individuals, who may retain critical environmental knowledge, is essential for sustaining elephant populations and the ecosystems they influence. Advancing research on elephant navigation and decision-making can provide valuable insights for biodiversity conservation and conflict mitigation efforts.

30 October 2026 in Journal of Zoology
Verified
Journal Article
Open access
RGRobert Guldemond
Robert Guldemond
SFSam M Ferreira
Sam M Ferreira
HLHannes Louw
Hannes Louw
YEYolandi Ernst
Yolandi Ernst
JPJohn Power
John Power
BCBernard W. T. Coetzee
Bernard W. T. Coetzee
Wildlife populations are regulated by immigration and emigration, as well as birth and death rates. When dispersal is not possible due to land use changes, population size is determined solely by births and deaths. Such is the case in many of South Africa's protected areas, where wildlife populations are well protected, intensively managed, and provided with artificial water sources, food, and custodial care. We used African savanna elephant ( Loxodonta africana ) populations in the Pilanesberg and Madikwe Nature Reserves, South Africa, as case studies to evaluate demographic responses to high density, insularity, and founder effects, especially during drier‐than‐normal periods. The incomplete age and sex structures of these founding elephant populations, combined with high age‐specific survival and fertility rates, led to transient dynamics and sustained high growth rates for an entire generation. The effect of adult survival on the modelled transient growth was greater than age at first calving or fecundity. However, the survival of weaned calves and juveniles made the most significant contribution to the transient dynamics in response to the recent dry conditions. Fences prevented dispersal and inhibited the density‐dependent mechanisms that typically stabilise growth near zero, as is the case when elephants can disperse and experience a range of resource gradients. Instead, we illustrate how density‐dependent demographic processes in the two elephant populations are already affecting their long‐term growth, including decreases in weaned calf and juvenile survival, increases in the age of first calving, and lower fecundity. These demographic signals should provide the basis for evaluating the population consequences of management interventions aimed at addressing the socio‐ecological impacts of elephants.