Jan Adriaan Venter

Jan Adriaan Venter
Nelson Mandela University | NMMU · School of Natural Resource Management, Faculty of Science

PhD

About

73
Publications
20,956
Reads
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462
Citations
Citations since 2017
48 Research Items
391 Citations
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2017201820192020202120222023020406080
Introduction
I am a conservation ecologist and a faculty member in the School of Natural Resource Management, Nelson Mandela University based on the George Campus. My research focuses on large terrestrial mammal ecology. See my Lab web page for more details: https://wildecolab.com/
Additional affiliations
June 2015 - December 2017
Nelson Mandela University
Position
  • Manager
January 2013 - present
University of Pretoria
Position
  • Extraordinary Lecturer
July 2009 - August 2014
University of KwaZulu-Natal
Position
  • PhD Student

Publications

Publications (73)
Article
Full-text available
Although tortoises (Testudinidae) are a familiar clade of reptiles, with a body fossil record extending to at least the Eocene, hitherto no tortoise ichnosites have been described. Here, a number of sites attributed to tortoise trackmakers are identified within Pleistocene aeolianites on South Africa's Cape south coast. These date from late Marine...
Article
Protected areas must be managed effectively if they are to contribute to reducing biodiversity loss, and one of the components of effective management is the development of biodiversity inventories. We conducted herpetofaunal surveys of the Mpofu-Fort Fordyce Nature Reserve complex in the Amathole District Municipality, Eastern Cape Province, South...
Conference Paper
Since the Pleistocene, there was a global decline in large mammals, with some 14% of large mammal species becoming extinct within Africa. In the southern Cape of South Africa, where megaherbivores have either become extinct or been extirpated, many protected areas are now reintroducing species for ecotourism. However, the ecological effects of thes...
Article
The breeding range of the Cape Gannet Morus capensis currently extends to six of the ten islands formerly utilised by this species. The Cape Gannet is classified as an endangered species with a rapidly declining population. Since the mid-1950s, the global population has declined by 51% due to multiple causes, including egg predation by the Kelp Gul...
Article
Helm, C.W.; Carr, A.S.; Cawthra, H.C.; De Vynck, J.C.; Dixon, M.; Stear, W.; Stuart, C.; Stuart, M., and Venter, J.A., 2022. Possible Pleistocene pinniped ichnofossils on South Africa's Cape south coast. Journal of Coastal Research, 38(4), 735749. Coconut Creek (Florida), ISSN 0749-0208. Exposed surfaces of cemented foreshore deposits and aeolianit...
Article
Full-text available
Seabird populations experience predation that can impact their breeding density and breeding success. The Cape gannet Morus capensis is endemic to the Benguela upwelling ecosystem and is classified as Endangered by the IUCN. They are affected by several threats, including predation by the Cape fur seal Arctocephalus pusillus pusillus . Many fledgli...
Article
en The Overberg area, Western Cape, South Africa is highly suitable for agricultural practices and has subsequently been severely transformed over the last four centuries. This has created a novel habitat for many wildlife species. The objective of this study was to determine the forage use of five antelope species and thereby assess their level of...
Article
Black-backed jackals (Canis mesomelas) are opportunistic mesopredators occupying a variety of ecosystems across South Africa (SA). They can move between protected areas (PAs) and surrounding human-dominated landscapes where they are prone to conflict with wildlife and livestock farmers and subsequently face high persecution rates. However, it remai...
Article
Full-text available
Throughout much of the Quaternary, lower sea levels in the southern Cape of South Africa exposed a different landscape to what we see today, the Palaeo-Agulhas Plain (PAP). The PAP was dominated by large-bodied and gregarious grazing species contrasting with the small-bodied predominantly solitary species we find in the region today. The distributi...
Article
Protected areas are intended as tools in reducing threats to wildlife and preserving habitat for their long-term population persistence. Studies on ranging behavior provide insight into the utility of protected areas. Vultures are one of the fastest declining groups of birds globally and are popular subjects for telemetry studies, but continent-wid...
Article
Context: The spatio-temporal partitioning of large carnivores is influenced by interspecific competition and coexistence within small, enclosed reserves. Lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) are the three largest African carnivores and have the greatest potential for intra-guild competition, particu...
Conference Paper
Activity patterns of carnivore species reflect temporal niche dimensions adapted to facilitate effective utilisation of resources, avoid risk and acclimate to physical environmental conditions. Therefore, to elucidate the use of time as a method of coexistence among carnivores, we assessed seasonal differences and overlap in daily activity patterns...
Conference Paper
Owing to costly, labour intensive or timeconsuming survey methods there is a lack of robust population data for cryptic carnivores in many areas. Population data are important for the management of these species in enclosed, fenced protected areas as species’ natural migratory patterns are restricted. In this study we used three different camera tr...
Article
Full-text available
Populations of carnivore species outside protected areas may be of considerable importance for conservation, as many protected areas do not provide sufficient space for viable populations. Data on carnivore population sizes and trends are often biased towards protected areas, and few studies have examined the role of unprotected areas for carnivore...
Conference Paper
Southern Africa has a diverse large carnivore guild. When this large carnivore guild is confined to small, fenced, protected areas, the degree of intraguild competition increases. Dietary overlap is a notable point of competition and can have considerable effects on subordinate trophic levels. We considered the prey preferences and dietary overlap...
Conference Paper
The spatio-temporal partitioning of large carnivores is influenced by interspecific competition and coexistence within small, enclosed reserves. Lions (Panthera leo), spotted hyaenas (Crocuta crocuta) and leopards (Panthera pardus) are the three largest African carnivores and have the greatest potential for intra-guild competition, particularly whe...
Article
Herbivore distribution throughout Africa is strongly linked to mean annual precipitation. We use that relationship to predict functional group composition of herbivore communities during the last glacial maximum (ca. 21 ka) on the now submerged Palaeo-Agulhas Plain (PAP), South Africa. We used metabolic large herbivore biomass (MLHB) from 39 South...
Article
Full-text available
Management and conservation actions are only as effective as our ability to monitor and assess biodiversity trends. We therefore compared the cost efficiency and effectiveness of several standard methods to assess mammal diversity using camera traps, live traps, track plates, mist nets for bats, acoustic bat surveys, spotlight surveys, and block tr...
Article
Full-text available
Pleistocene aeolianite surfaces on the South African coastline, which occur in national parks, other protected areas, as well as unprotected areas, are of profound scientific, cultural, palaeoenvironmental and heritage importance. A threat is posed to these surfaces by the increasing presence of graffiti, which may deface or destroy fossil tracksit...
Article
Full-text available
Nature is experiencing degradation and extinction rates never recorded before in the history of Earth.1,2 Consequently, continuous large-scale monitoring programmes are critical, not only to provide insights into population trends but also to aid in understanding factors associated with altering population dynamics at various temporal and spatial s...
Article
Full-text available
Large herbivores form an essential component in the ecosystem, because of the impact that they have on their surrounding habitat. In this study, we aimed to evaluate some of the mechanisms behind how herbivores select forage at a patch scale. Thirty-six experimental plots were established and fitted with camera traps in Kruger National Park to test...
Article
The Greater Cape Floristic Region of South Africa was critical to the evolution of early modern humans (Homo sapiens) during the Pleistocene. The now submerged continental shelf formed its own ecosystem, the Palaeo-Agulhas Plain (PAP), where early humans lived and foraged. Grazing animals living on the plain might have migrated east and west tracki...
Article
Full-text available
The subtle and cascading effects (e.g., altered interspecific interactions) that anthropogenic stressors have on local ecological assemblages often go unnoticed but are concerning given their importance in ecosystem function. For example, elimination of buffalo from the Serengeti National Park is suggested to have driven increased abundance of smal...
Article
Roost site preferences influence the spatial distribution of species. Large soaring birds often roost on cliffs and large structures, and thus are restricted to areas where safe takeoffs and landings can occur. The cliff roosting preferences of the Cape Vulture Gyps coprotheres were explored for five juveniles and nine adult birds. Generalised line...
Article
Full-text available
The distribution and abundance of herbivores in African savannas are constrained by interactions between abiotic and biotic factors. At the species-level, herbivores face trade-offs among foraging requirements, vegetation structure and the availability of surface water that change over spatial and temporal scales. Characterizing herbivore requireme...
Article
Recent evidence indicates that the now submerged continental shelf, the Palaeo-Agulhas Plain (PAP), formed a novel ecosystem during periods of low sea level. This landscape provided nutrient-rich forage and habitats to a variety of large mammals. This is in contrast to the modern faunal assemblage found in the present-day Cape Floristic Region, whi...
Chapter
Grazers and browsers are adapted to survive and utilize forage in a wide range of different environments globally. There are major differences in the forage sources they utilize. These differences can be observed from a plant part’s chemical structure up to biome distribution in relation to global climate. As a result there are many differences as...
Poster
Species-specific population data is important for the effective management and conservation of wildlife populations within protected areas. Spotted hyaena (Crocuta crocuta) population density will be determined for Madikwe Game Reserve. Individual photos will be collected over a three-month period opportunistically. These images will be combined wi...
Conference Paper
As we see a trend towards small fenced conservation areas across Africa, reintroductions are an increasingly important conservation tool. Species-specific population data is important for the effective management and conservation of wildlife populations within protected areas. Spotted hyaena (Crocuta Crocuta) population data will be determined for...
Article
Body fossil remains usually provide the main palaeontological resource for palaeoecological studies. Ichnology has the capacity to independently complement such data. Fossil tracksites provide a direct record of animals whose tracks have been preserved, and with regard to the Palaeo-Agulhas Plain they have direct relevance in considering palaeoecol...
Article
Full-text available
The Palaeo-Agulhas Plain formed an important habitat exploited by Pleistocene hunter-gatherer populations during periods of lower sea level. This productive, grassy habitat would have supported numerous large-bodied ungulates accessible to a population of skilled hunters with the right hunting technology. It also provided a potentially rich locatio...
Article
Understanding and quantifying a large carnivores’ feeding behaviour is a key component in determining its functional significance in an ecosystem, both in terms of its top‐down influence on prey species, but also its relationships with sympatric carnivores. Dietary overlap is one of the numerous niche dimensions used to characterize resource partit...
Article
The endangered Cape vulture (Gyps coprotheres) is facing a new emerging threat, e.g. wind energy development. Given their vulnerability to wind energy infrastructure, there is a necessity to establish proactive measures that could potentially mitigate future collisions, such as conservation buffers around breeding colonies and roost sites. This stu...
Article
Full-text available
East of Still Bay on the Cape south coast of South Africa lies a rugged, remote stretch of sea cliffs that expose Late Pleistocene aeolianites. A zone of dense concentration of fossil tracks occurs within this area. Two large rocks, which we call Roberts Rock and Megafauna Rock, were identified ~400 metres apart. These rocks contained a variety of...
Article
Full-text available
Restoring large predators to small confined areas (< 400 km²) is inherently complex and therefore any data on the foraging behaviour and top-down influences hold significant value for the conservation and reintroduction planning of the species. Conservation efforts are increasingly applied to small or fragmented landscapes. However, it is unclear w...
Article
The post-fledging dependence period (PFDP) is one of the most critical stages in the life history of some avian species. Birds are particularly sensitive to mortality during this stage as they must learn essential skills, such as efficient locomotion, proficient food location and predator avoidance. Knowledge of the PFDP would provide valuable info...
Article
Full-text available
Understanding fire regimes in the coastal region of the Pondoland center of plant endemism, (Eastern Cape, South Africa) is of critical importance, especially in areas where anthropogenic ignitions influence the fire regime. We characterized the fire regime (2007 to 2016) of Mkambati Nature Reserve (9200 ha) in terms of fire season, seasonality of...
Article
Full-text available
Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have no a priori knowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits improve their efficie...
Preprint
Full-text available
Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have no a priori knowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits, improve their effici...
Preprint
Full-text available
Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have no a priori knowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits, improve their effici...
Article
Full-text available
Ingestion of man-made items by birds can reduce stomach volume and block the digestive track. In southern Africa, microtrash within the regurgitation of Cape Vulture nestlings was last documented in 1983. We present evidence of nestling microtrash ingestion after a 30-year gap. Vulture nestlings were captured at a breeding colony in the Eastern Cap...
Technical Report
Full-text available
Assessment Rationale: Considering its relatively widespread distribution, ability to utilise agricultural landscapes, and common occurrence (occurring at 0.3 and 0.5 individuals / km² in Cape forests), the Bushpig is listed as Least Concern within the assessment region. No major threats have been identified that may be causing significant declines...
Technical Report
Full-text available
Assessment Rationale: This sub-Saharan African species has a disjunct distribution between the eastern coastal forests of South Africa and the rest of its range. Within the assessment region, the species is inferred to be declining due to forest habitat loss from ongoing development along the coastal belt, illegal sand mining (which may represent...
Article
The breeding success of endangered colonial nesting species is important for their conservation. Many species of Gyps vultures form large breeding colonies that are the foci of conservation efforts. The Cape Vulture is a globally threatened species that is endemic to southern Africa and has seen a major reduction in its population size (≥50% over 4...
Article
Full-text available
We used stable carbon isotopes from faeces to investigate the proportional contribution of C 3 and C 4 plant forms to the diet of the herbivores in Mkambati Nature Reserve, a grassland dominated ecosystem on the east coast of South Africa. Our results indicate that Equus burchellii, Damaliscus pygargus phillipsi, and Alcelaphus buselaphus utilize m...
Article
Full-text available
The results of herpetofaunal surveys of Oviston, Commando Drift and Tsolwana nature reserves in central and northern Eastern Cape, South Africa are presented. Visual encounter survey methods and standard Y-shape trap arrays were used to conduct surveys from 2014 to 2015. A total of 58 species (12 amphibians and 44 reptiles) were recorded and 130 qu...
Article
Full-text available
We surveyed six protected areas along the Wild Coast of the Eastern Cape, South Africa, to determine general herpetofaunal diversity as well as the representation of species of special conservation concern. Visual encounter survey methods and standard Y-shape trap arrays were used to conduct surveys from 2011 to 2013. A total of 59 species (22 amph...
Article
Full-text available
Understanding environmental as well as anthropogenic factors that influence large herbivore ecological patterns and processes should underpin their conservation and management. We assessed the influence of intrinsic, extrinsic environmental and extrinsic anthropogenic factors on movement behaviour of eight African large herbivore species. A cumulat...
Article
Full-text available
Despite the extent of subsistence farmland in Africa, little is known about endangered species that persist within them. The Cape Vulture (Gyps coprotheres) is regionally endangered in southern Africa and at least 20% of the population breeds in the subsistence farmland area previously known as the Transkei in the Eastern Cape province of South Afr...
Article
Full-text available
Resource use of Cape mountain zebra was studied in the Baviaanskloof Nature Reserve (BNR) over concerns of the poor performance in population growth. We assessed the seasonal diet, habitat suitability and forage quality of the Bergplaas area in BNR for mountain zebra. Grasses contributed 95.2% to the annual diet of mountain zebra, Tristachya leucot...
Article
Full-text available
Declines in Old World vulture populations have been linked to anthropogenic pressures. To assess these threats, the social dimensions of vulture conservation must be explored. Prior research in Africa focused on commercial farmers’ perceptions of vultures and identified that small stock farmers used poison more than large stock farmers to deter liv...
Thesis
Full-text available
Understanding the intrinsic and extrinsic influences that affect large herbivore assemblages are important for protected area managers, especially if their current rate of population decline in Africa continues. I aimed to determine how large herbivore species in African grazing ecosystems, respond to intrinsic and extrinsic influences, and the imp...
Article
Full-text available
Understanding how different herbivores make for-age patch use choices explains how they maintain an adequate nutritional status, which is important for effective conserva-tion management of grazing ecosystems. Using telemetry data, we investigated nonruminant zebra (Equus burchelli) and ruminant red hartebeest (Alcelaphus buselaphus subspe-cies cam...
Article
Full-text available
Protected area management agencies often struggle to reliably reconstruct grazer assemblages due to a lack of historical distribution data for their regions. Wrong predictions of grazing assemblages could potentially affect biodiversity negatively. The objective of the study was to determine how well grazing herbivores have become established since...
Article
Full-text available
This paper summarizes the results of a recent survey of the South African “Wild Coast” in Pondoland, Eastern Cape Province. The purpose of the survey was to locate and to describe coastal caves and rock shelters that may contain Early and Middle Stone Age archaeological deposits for future study. The study is part of a much larger research design t...
Article
Full-text available
A preliminary assessment of surf-zone and estuarine line fish was carried out in the Dwesa-Cwebe Marine Protected Area (MPA), on the Wild Coast, South Africa. The purpose was to provide baseline data on inshore line-fish stocks in the MPA. A total of 28 species was recorded, of which 53% have a conservation status reflecting some concern and 43% ar...
Article
Full-text available
Data collected at two sites in the Luvuvhu and Sabie rivers show that, based on the gonadosomatic index, Opsaridium peringueyi has one major annual breeding event that occurs in early summer, following a period during which the general condition of fish improves. Visual observation and microscopic measurement of oocyte sizes show that females reach...
Article
Full-text available
In South Africa, relatively small, but healthy populations of Opsaridium peringueyi remain in the middle reaches of the Luvuvhu, Blyde, Sabie and Pongolo Rivers. The species may be extinct in some rivers like the Shingwedzi and lower-Olifants and its status is uncertain in the Crocodile and lower Komati/Mlumati Rivers. In many cases the rivers are...
Article
Full-text available
Here we studied the the diet and habitat use of buffalo (Syncerus caffer caffer) on Doornkloof Nature Reserve (DNR) in the Nama-Karoo, South Africa. The buffalo were predominantly grazers. Only seven grass species formed the bulk of their diet and marked seasonal shifts were observed in the contribution of these species to the diet of buffalo. Erag...
Article
Full-text available
Two groups of Cape buffalo (Syncerus caffer) were released on Doornkloof Nature Reserve. The first group of four subadult animals was introduced in 2000 and the second group of seven adult and three subadult animals in 2002. Both groups were kept in short-term confinement for a few weeks before they were released. The first group showed several beh...

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